Gun Owners of America, Inc. v. Merrick B. Garland ( 2021 )


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  •                                       RECOMMENDED FOR PUBLICATION
    Pursuant to Sixth Circuit I.O.P. 32.1(b)
    File Name: 21a0279p.06
    UNITED STATES COURT OF APPEALS
    FOR THE SIXTH CIRCUIT
    ┐
    GUN OWNERS OF AMERICA, INC.; GUN OWNERS
    │
    FOUNDATION; VIRGINIA CITIZENS DEFENSE LEAGUE;
    │
    MATT WATKINS; TIM HARMSEN; RACHEL MALONE,
    │
    Plaintiffs-Appellants,                │
    >        No. 19-1298
    │
    GUN OWNERS OF CALIFORNIA, INC.,                                   │
    Movant,      │
    │
    v.                                                     │
    │
    │
    MERRICK B. GARLAND, in his official capacity as                   │
    Attorney General of the United States; UNITED STATES              │
    DEPARTMENT OF JUSTICE; BUREAU OF ALCOHOL,                         │
    TOBACCO, FIREARMS AND EXPLOSIVES; REGINA                          │
    LOMBARDO, in her official capacity as Acting                      │
    Director, Bureau of Alcohol, Tobacco, Firearms, and               │
    Explosives,                                                       │
    Defendants-Appellees.              │
    ┘
    On Petition for Rehearing En Banc.
    United States District Court for the Western District of Michigan at Grand Rapids;
    No. 1:18-cv-01429—Paul Lewis Maloney, District Judge.
    Argued: October 20, 2021
    Decided and Filed: December 3, 2021
    SUTTON, Chief Judge; BATCHELDER, MOORE, COLE, CLAY, GIBBONS,
    GRIFFIN, KETHLEDGE, WHITE, STRANCH, DONALD, THAPAR,
    BUSH, LARSEN, NALBANDIAN and MURPHY, Circuit Judges.*
    *
    Pursuant to 6 Cir. I.O.P. 35(c), Composition of the En Banc Court, Judge Batchelder, a senior judge of the
    court who sat on the original panel in this case, participated in this decision. Judge Readler recused himself from
    participation in this decision.
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                      Page 2
    _________________
    COUNSEL
    ARGUED: Robert J. Olson, WILLIAM J. OLSON, P.C., Vienna, Virginia, for Appellants.
    Mark B. Stern, UNITED STATES DEPARTMENT OF JUSTICE, Washington, D.C., for
    Appellees. ON BRIEF: Robert J. Olson, WILLIAM J. OLSON, P.C., Vienna, Virginia, Kerry
    L. Morgan, PENTIUK, COUVREUR & KOBILJAK, P.C., Wyandotte, Michigan, for
    Appellants. Mark B. Stern, Abby C. Wright, Brad Hinshelwood, Kyle T. Edwards, UNITED
    STATES DEPARTMENT OF JUSTICE, Washington, D.C., for Appellees. Alan Alexander
    Beck, San Diego, California, Stephen D. Stamboulieh, STAMBOULIEH LAW, PLLC, Olive
    Branch, Mississippi, Michael T. Jean, Hadan W. Hatch, NATIONAL RIFLE ASSOCIATION
    OF AMERICA, Fairfax, Virginia, John I. Harris III, SCHULMAN, LEROY & BENNETT PC,
    Nashville, Tennessee, Sebastian D. Torres, BISGAARD & SMITH LLP, Cincinnati, Ohio, Ilya
    Shapiro, CATO INSTITUTE, Washington, D.C., Richard A. Samp, NEW CIVIL LIBERTIES
    ALLIANCE, Washington, D.C., David M. S. Dewhirst, OFFICE OF THE MONTANA
    ATTORNEY GENERAL, Helena, Montana, Joseph G. S. Greenlee, FIREARMS POLICY
    COALITION, Sacramento, California, Ian Simmons, O’MELVENY & MYERS LLP,
    Washington, D.C., John Cutonilli, Garrett Park, Maryland, pro se, for Amici Curiae.
    The En Banc Court of the Sixth Circuit Court of Appeals delivered an order. WHITE, J.
    (pp. 3–20), in which MOORE, COLE, CLAY, and STRANCH, JJ., joined, and GIBBONS, J.
    (pg. 21), in which MOORE, COLE, WHITE, and STRANCH, JJ., joined, delivered separate
    opinions in support of affirming the district court’s judgment. MURPHY, J. (pp. 22–47),
    delivered a separate dissenting opinion, in which SUTTON, C.J., BATCHELDER,
    KETHLEDGE, THAPAR, BUSH, LARSEN, and NALBANDIAN, JJ., joined.
    _________________
    ORDER
    _________________
    Pursuant to Rule 35 of the Federal Rules of Appellate Procedure and Sixth Circuit Rule
    35, a majority of the active judges of this court voted to grant en banc review of this case.
    By published order of the court, entered on June 25, 2021, rehearing en banc was granted and the
    previous opinion was vacated. Following argument heard by the court en banc on October 20,
    2021 and a conference among the judges, the court divided evenly, with eight judges voting to
    affirm the judgment of the district court and eight judges voting to reverse. Consequently, the
    judgment of the district court is AFFIRMED. See School Dist., Pontiac v. Secretary, U.S. Dep’t.
    Educ., 
    584 F.3d 253
     (6th Cir. 2009), Goodwin v. Ghee, 
    330 F.3d 446
     (6th Cir. 2003), and
    Stupak-Thrall v. United States, 
    89 F.3d 1269
     (6th Cir. 1996). Separate opinions in favor of
    affirmance and in favor of reversal follow.
    No. 19-1298                           Gun Owners of Am., Inc. v. Garland                          Page 3
    ___________________________________________________________________________
    OPINION IN SUPPORT OF AFFIRMING THE DISTRICT COURT’S JUDGMENT
    ___________________________________________________________________________
    WHITE, Circuit Judge, writing in support of affirming the district court judgment.
    Congress defined the term, “machinegun,” to mean “any weapon which shoots, is designed to
    shoot, or can be readily restored to shoot, automatically more than one shot, without manual
    reloading, by a single function of the trigger.” 26 U.S.C. § 5845(b). “Machinegun” also
    includes “the frame or receiver of any such weapon” as well as “any part designed and intended
    solely and exclusively, or combination of parts designed and intended, for use in converting a
    weapon into a machinegun, and any combination of parts from which a machinegun can be
    assembled if such parts are in the possession or under the control of a person.” Id.
    And Congress tasked the Attorney General with administering and enforcing Chapter 53
    of Title 26 of the National Firearms Act, in which the definition of “machinegun” appears, and
    delegated rulemaking authority to the Attorney General to further this end.                     26 U.S.C.
    §§ 7801(a)(2)(A), 7805(a). Congress also authorized the Attorney General to prescribe “rules
    and regulations as are necessary to carry out the provisions” of Chapter 44 of Title 18 of the Gun
    Control Act. 18 U.S.C. § 926(a). The Gun Control Act makes it unlawful to transfer or possess
    a “machinegun” as defined in § 5845(b). 18 U.S.C. §§ 921(a)(23), 922(o).
    The Attorney General has directed the Director of the Bureau of Alcohol, Tobacco,
    Firearms and Explosives (ATF) to administer, enforce, and exercise the functions and powers of
    the Attorney General with respect to Chapter 44 of Title 18 and Chapter 53 of Title 26.
    28 C.F.R. § 0.130(a). On December 26, 2018, ATF published a rule clarifying that bump-stock-
    type devices fall within the definition of “machinegun” as defined in the National Firearms Act
    and the Gun Control Act.1 Bump-Stock-Type Devices (Final Rule), 
    83 Fed. Reg. 66,514
    ,
    66,543.2
    1
    The district court succinctly described bump-stock-type devices:
    The stock of a rifle is the portion of the weapon behind the trigger and firing mechanism and
    extends rearward towards the shooter. The forward part of the stock just behind the trigger
    No. 19-1298                            Gun Owners of Am., Inc. v. Garland                                       Page 4
    Plaintiffs-Appellants (Gun Owners) filed this action challenging the Final Rule and sought a
    preliminary injunction to prevent it from going into effect. Gun Owners of Am. v. Barr, 
    363 F. Supp. 3d 823
    , 825–26 (W.D. Mich. 2019), rev’d and remanded sub nom. Gun Owners of Am.,
    Inc. v. Garland, 
    992 F.3d 446
     (6th Cir. 2021), reh’g en banc granted, opinion vacated, 
    2 F.4th 576
     (6th Cir. 2021). The district court concluded that Chevron’s two-step test provides the
    appropriate standard of review to determine whether injunctive relief is warranted. 
    Id. at 830
    –31
    (citing Chevron U.S.A., Inc. v. Nat. Res. Def. Council, 
    467 U.S. 837
    , 842–43 (1984)). First, the
    district court found that Congress has not directly addressed whether bump stocks are included
    within the statutory term “machinegun” and that the definitional terms, “automatically” and
    “single function of the trigger,” are ambiguous. 
    Id. at 831
    . Second, the district court determined
    that the Final Rule’s interpretations of “automatically” and “single function of the trigger” are
    permissible and its classification of bump stocks as machineguns is reasonable. 
    Id. at 831
    –32.
    Concluding that Gun Owners failed to demonstrate a likelihood of success on the merits, the
    district court denied the motion for a preliminary injunction.3 
    Id. at 832
    –33.
    provides a grip for the shooting hand. The rear end of the stock rests against the shooter's
    shoulder. A bump stock replaces the standard stock on a rifle. Bump stocks include an extension
    ledge or finger rest on which the shooter places his or her trigger finger where it is stabilized. The
    shooter then exerts a constant forward pressure on the barrel of the rifle using the non-trigger
    hand. As the rifle is pushed forward, the shooter also pulls the trigger, initiating the firing
    sequence. The bump stock then harnesses the rearward recoil energy from the shot causing the
    weapon to slide back into shooter’s shoulder separating the trigger finger resting on the ledge and
    the trigger itself. The constant forward pressure exerted by the non-trigger hand on the barrel then
    pushes the weapon forward "bumping" the weapon against the stationary trigger finger. The back-
    and-forth sequence allows a shooter to fire a semiautomatic rifle at rates similar to automatic
    rifles.
    Gun Owners of Am. v. Barr, 
    363 F. Supp. 3d 823
    , 828–29 (W.D. Mich. 2019).
    2
    After a mass shooting in Las Vegas, Nevada, in October 2017, members of Congress and several
    nongovernmental organizations asked ATF to examine whether bump-stock-type devices constitute machineguns.
    Final Rule, 83 Fed. Reg. at 66,516. The Las Vegas shooter fired several hundred rounds in a short span of time—
    murdering scores of persons and wounding hundreds more—by using bump-stock-type devices attached to his rifles.
    
    Id. 3
    Before ruling on the motion, the district court correctly concluded that ATF’s interpretations are not
    arbitrary or capricious. Gun Owners, 363 F. Supp. 3d at 832–33. The Final Rule acknowledges ATF’s previous
    treatment of bump stocks as not meeting the definition of machinegun and sets forth sufficient reasons for the new
    interpretations. 
    83 Fed. Reg. 66,514
    , 66,517–19. The Final Rule also adequately explains why bump stocks are
    treated differently than other objects, such as belt loops, that can assist in bump firing, and it sufficiently responds to
    the concern that semiautomatic guns without bump stocks could be improperly classified as machineguns. 
    Id. at 66,
    533–34. Finally, regarding Gun Owners’ new assertion that the political outcry following the mass shooting in
    Las Vegas—the likely cause of then-President Trump’s call on ATF to review the matter—somehow tainted the
    No. 19-1298                          Gun Owners of Am., Inc. v. Garland                                   Page 5
    The district court’s judgment should be affirmed. Chevron provides the standard of
    review, even though the law under consideration has criminal applications. Applying Chevron,
    Congress has not spoken to the precise question at issue and, after exhausting the traditional tools
    of statutory construction, § 5845(b) remains ambiguous.                    Because ATF’s interpretation of
    § 5845(b) is a permissible construction of the statute and is reasonable, it is entitled to Chevron
    deference. Additionally, even without applying deference, the Final Rule provides the best
    interpretation of § 5845(b). Accordingly, relief to enjoin the Final Rule from going into effect is
    not warranted.
    I. Chevron Applies
    We apply Chevron when “Congress delegated authority to the agency generally to make
    rules carrying the force of law” and “the agency interpretation” in question “was promulgated in
    the exercise of that authority.” United States v. Mead Corp., 
    533 U.S. 218
    , 226–27 (2001)
    (“Delegation of such authority may be shown . . . by an agency’s power to engage in . . . notice-
    and-comment rulemaking, or by some other indication of comparable congressional intent.”).
    Here, Congress expressly delegated rulemaking authority to the Attorney General, who delegated
    this authority to the director of ATF. 18 U.S.C. § 926(a); 26 U.S.C. §§ 7801(a)(2)(A), 7805(a);
    28 C.F.R. § 0.130(a).         ATF then promulgated the Final Rule through notice-and-comment
    rulemaking, expressly invoking § 926(a) (authority to promulgate rules and regulations as are
    necessary to carry out provisions of the Gun Control Act), § 7801(a)(2)(A) (authority to
    administer and enforce provisions of the National Firearms Act), and § 7805(a) (authority to
    promulgate all needful rules and regulations to enforce provisions of the National Firearms
    Act).4 Final Rule, 83 Fed. Reg. at 66,515–16; see also Bump-Stock-Type Devices, 
    83 Fed. Reg. 13,442
    , 13,443–44 (notice of proposed rulemaking). Thus, Chevron supplies the standard of
    rulemaking process, “that is hardly a reason to conclude that the Rule is arbitrary. Presidential administrations are
    elected to make policy.” Guedes v. Bureau of Alcohol, Tobacco, Firearms & Explosives, 
    920 F.3d 1
    , 34 (D.C. Cir.
    2019).
    4
    Moreover, when responding to comments submitted in opposition to the proposed rule, ATF described,
    over several paragraphs, how Chevron would apply if the terms “automatically” and “single function of the trigger”
    were ambiguous, and how ATF’s construction of these terms is reasonable under Chevron. Final Rule, 83 Fed. Reg.
    at 66,527. This “exegesis on Chevron would have served no purpose unless the agency intended the Rule to be
    legislative in character.” Guedes, 920 F.3d at 19. Additionally, all other pertinent indicia of agency intent confirm
    that the Final Rule is a legislative rule. Id. at 18–19; accord Aposhian v. Barr, 
    958 F.3d 969
    , 980 (10th Cir. 2020).
    No. 19-1298                           Gun Owners of Am., Inc. v. Garland                                    Page 6
    review for assessing the validity of the Final Rule’s classification of bump-stock-type devices as
    machineguns.5
    Gun Owners and my colleagues who argue for reversal assert that ATF’s delegated
    authority is too general for Chevron deference to apply. Drawing a distinction between explicit
    and implied delegations to an agency, and relying on pre-Chevron cases, they discount precedent
    applying Chevron to regulations that have criminal applications. However, Chevron itself does
    not suggest the distinction between implicit and express delegations of rulemaking authority that
    underlies the opinion to reverse. 
    467 U.S. at 843
    –44 (“The power of an administrative agency to
    administer a congressionally created . . . program necessarily requires the formulation of policy
    and the making of rules to fill any gap left, implicitly or explicitly, by Congress. . . . Sometimes
    the legislative delegation to an agency on a particular question is implicit rather than explicit.”
    (internal quotation marks and citation omitted)). And the Supreme Court has made clear that
    Chevron deference is not eliminated simply because the rulemaking authority conferred the
    Attorney General (and ATF, by extension) was not specified with exactitude. Mayo Found. for
    Med. Educ. & Rsch. v. United States, 
    562 U.S. 44
    , 56–57 (2011) (establishing that Chevron
    deference is appropriate when Congress delegated authority to make rules carrying the force of
    law generally and the agency interpretation was promulgated in the exercise of that authority,
    and stating “[o]ur inquiry in that regard does not turn on whether Congress’s delegation of
    authority was general or specific”).
    Moreover, the Supreme Court has considered—and rejected—the premise that an implicit
    delegation somehow confers less authority than an explicit delegation. In City of Arlington v.
    F.C.C., the dissent argued that Chevron deference should apply only where a delegation of
    5
    Gun Owners argues that ATF waived Chevron by disclaiming any reliance on it in this litigation. But, if
    we were to recognize such litigation positions as effective waivers in the context of legislative rules, we would allow
    agencies to evade the Administrative Procedure Act’s requirement to use the same notice-and-comment process to
    amend or repeal a rule as used to promulgate it. See Guedes, 920 F.3d at 22–23. Further, whether to apply Chevron
    is a question for the court to decide, not an agency’s lawyers. SoundExchange, Inc. v. Copyright Royalty Bd., 
    904 F.3d 41
    , 54 (D.C. Cir. 2018). HollyFrontier Cheyenne Refinery, LLC v. Renewable Fuels Ass’n, in which the
    Supreme Court, in a short paragraph, declined to consider whether Chevron deference was due, does not alter this
    conclusion. 
    141 S. Ct. 2172
    , 2180 (2021). HollyFrontier dealt only with an agency’s attempt to use an unrelated
    rule, the validity of which was not in dispute, to demonstrate the validity of the unpublished agency orders being
    challenged. 
    Id.
     That is, the Court did not address whether Chevron deference could be waived with respect to a
    disputed legislative rule. Nor did it hold that courts are prohibited from applying Chevron when an agency decides
    not to rely on it in litigation.
    No. 19-1298                          Gun Owners of Am., Inc. v. Garland                                  Page 7
    authority covered the “specific provision” before the court. 
    569 U.S. 290
    , 322–23 (2013)
    (Roberts, C.J., dissenting). The majority rejected this argument, noting that the dissent could not
    produce “a single case in which a general conferral of rulemaking or adjudicative authority has
    been held insufficient to support Chevron deference for an exercise of that authority within the
    agency’s substantive field.” 
    Id. at 306
    . The Court declined to adopt this proposed “massive
    revision of our Chevron jurisprudence.” 
    Id.
     We must do so today. Applying the statute to
    determine whether a device constitutes a machinegun is within ATF’s substantive field. See,
    e.g., United States v. Dodson, 519 F. App’x 344, 348 (6th Cir. 2013); Akins v. United States,
    312 F. App’x 197, 198 (11th Cir. 2009) (per curiam); F.J. Vollmer Co. v. Higgins, 
    23 F.3d 448
    ,
    449–50 (D.C. Cir. 1994); York v. Sec’y of Treasury, 
    774 F.2d 417
    , 419 (10th Cir. 1985).
    Additionally, the Supreme Court has rejected application of pre-Chevron tests in favor of
    “maintaining a uniform approach to judicial review of administrative action.” Mayo, 
    562 U.S. at 55
     (quoting Dickinson v. Zurko, 
    527 U.S. 150
    , 154 (1999)) (rejecting application of special
    pre-Chevron rules for reviewing Treasury regulations). Ultimately, the express/implied and
    specific/general distinctions have no role to play in applying Chevron deference.
    Those who argue for reversal also claim that Chevron does not apply because the Final
    Rule may impose criminal sanctions. However, this is not what the case law says. Chevron
    itself involved an agency interpretation with criminal applications—at the time, a knowing
    violation of one of the disputed legislative rule’s requirements was punishable by daily $25,000
    fines and imprisonment for up to a year—and yet the Supreme Court applied deference.
    
    467 U.S. at 866
    ; see also 42 U.S.C. §§ 7502, 7413. In another case, Babbitt v. Sweet Home
    Chapter of Communities for a Greater Oregon, the Court applied Chevron when reviewing a
    legislative rule that attached criminal penalties. 
    515 U.S. 687
    , 703–04 (1995). And in yet
    another case, United States v. O’Hagan, a criminal case, the Supreme Court applied Chevron
    deference to a legislative rule despite the rule’s clear criminal applications and penalties.
    
    521 U.S. 642
    , 673 (1997). What these cases make clear is that Chevron does not fall away
    simply because a challenged legislative rule has some criminal applications.6
    6
    United States v. Apel, 
    571 U.S. 359
     (2014), and Abramski v. United States, 
    573 U.S. 169
     (2014), do not
    compel a contrary conclusion. Neither involved a legislative rule and, thus, neither involved agency interpretations
    No. 19-1298                          Gun Owners of Am., Inc. v. Garland                                    Page 8
    The relevant question is whether Congress delegated to the agency authority to
    promulgate legislative rules with criminal applications. And, when the statute gives an agency
    broad power to enforce or administer all provisions of the statute, it is “clear” that the agency has
    the necessary authority to do so. See Gonzales v. Oregon, 
    546 U.S. 243
    , 258–59 (2006). Here,
    Congress broadly tasked the Attorney General with promulgating “such rules and regulations as
    are necessary to carry out the provisions” of the Gun Control Act—a purely criminal statute—
    and to “administ[er] and enforce[]” and “prescribe all needful rules and regulations for the
    enforcement” of the National Firearms Act—a statute with criminal applications. 18 U.S.C.
    §§ 924(a)(2), 926(a); 26 U.S.C. §§ 5871, 7801(a)(2)(A), 7805(a). This statutory context clearly
    demonstrates that Congress intended the authority delegated under the Gun Control Act and the
    National Firearms Act to encompass legislative rules with criminal applications. Guedes v.
    Bureau of Alcohol, Tobacco, Firearms & Explosives, 
    920 F.3d 1
    , 25–26 (D.C. Cir. 2019).
    Further, the rule of lenity does not displace Chevron simply because an agency has
    interpreted a statute carrying criminal penalties.              The Supreme Court considered this very
    question in Babbitt and said:
    We have applied the rule of lenity in a case raising a narrow question concerning
    the application of a statute that contains criminal sanctions to a specific factual
    dispute . . . where no regulation was present. We have never suggested that the
    rule of lenity should provide the standard for reviewing facial challenges to
    administrative regulations whenever the governing statute authorizes criminal
    enforcement.
    
    515 U.S. at 703
    –04, 704 n.18 (citation omitted). To be sure, the Babbitt Court also hypothesized
    that a regulation may “provide such inadequate notice of potential liability so as to offend the
    rule of lenity,” but this is simply an acknowledgment that a law imposing criminal sanctions—
    whether it be a statute or a regulation—must provide fair notice of the prohibited conduct. 
    Id. at 704 n.18
    .
    that would trigger Chevron. Nor do they mention Chevron, Babbitt, or O’Hagan and, thus, Apel and Abramski
    should not be read to overrule this precedent. To be sure, there is an implied tension between the two lines of cases,
    but this is for the Supreme Court to resolve, not us. Until the Court does so, we must follow Chevron, Babbitt, and
    O’Hagan. See Esquivel-Quintana v. Lynch, 
    810 F.3d 1019
    , 1023–24 (6th Cir. 2016), rev’d on other grounds sub
    nom. Esquivel-Quintana v. Sessions, 
    137 S. Ct. 1562
     (2017).
    No. 19-1298                            Gun Owners of Am., Inc. v. Garland                                       Page 9
    The Babbitt Court went on to determine that “the ‘harm’ regulation, which has existed for
    two decades and gives fair warning of its consequences,” was not such a rule-of-lenity-violating
    regulation. 
    Id.
     To read this sentence to mean that a regulation that breaks from a previous
    interpretation likely offends the rule of lenity is to apply false logic. Although the Court
    suggested that a longstanding regulation could hardly be expected to offend the rule of lenity, it
    did not suggest the converse—that any new, contrary interpretation would, by itself, trigger
    doubt.       And, based on the remainder of the sentence, fair warning of the regulation’s
    consequences—in and of itself, with no relation to the age of a regulation or whether it effected a
    reversal in position—would undermine the rule of lenity’s applicability.7 Further, “[a]gency
    inconsistency is not a basis for declining to analyze the agency’s interpretation under the
    Chevron framework.” Nat’l Cable & Telecomms. Ass’n v. Brand X Internet Servs., 
    545 U.S. 967
    , 981 (2005).
    Here, as in Babbitt, there is a legislative regulation—the Final Rule—which was
    promulgated under authority delegated to an agency and involves the interpretation of a statute
    with criminal applications.8 
    83 Fed. Reg. 66,514
    ; see also 18 U.S.C. §§ 924(a)(2), 926(a);
    26 U.S.C. §§ 5845(b), 5871, 7801(a)(2)(A), 7805(a); 28 C.F.R. § 0.130(a). There is no dispute
    7
    Even if the Final Rule were to be attacked in relation to its application to a specific factual dispute, it
    underwent the notice-and-comment process and over 186,000 comments were received, including one by Gun
    Owners on behalf of more than 1.5 million gun owners. The Final Rule was also published in the Federal Register.
    It is doubtful that these procedures provide such inadequate notice of potential liability as to offend the rule of
    lenity. See Guedes, 920 F.3d at 28.
    8
    The circumstances in Babbitt are analogous to the circumstances here. In Babbitt, Congress defined the
    word “take” but did not further define the terms it used to define “take.” 
    515 U.S. at 691
    . An agency interpreted
    one of the definitional terms—“harm”—to include habitat modification. The plaintiffs challenged that
    interpretation, arguing that Congress did not intend “take” to mean habitat modification. 
    Id. at 691, 693
    . In the
    instant case, Congress defined “machinegun” using the terms “automatically” and “single function of the trigger”
    without further defining these terms. ATF interpreted “automatically” and “single function of the trigger” to mean,
    in conjunction, “a single pull of the trigger” to initiate “a self-acting or self-regulating mechanism” to allow
    “continuous firing without additional physical manipulation of the trigger by the shooter,” which has the effect of
    including bump-stock-type devices as machineguns. Final Rule, 83 Fed. Reg. at 66,553–54. Gun Owners
    challenges this interpretation, arguing that Congress did not intend “machinegun” to include bump stocks.
    My colleagues favoring reversal distinguish Babbitt on the basis that it is an express-delegation case, whereas
    neither the National Firearms Act nor the Gun Control Act explicitly authorizes the Attorney General to issue
    regulations with criminal applications. But, again, when a statute gives an agency broad power to enforce or
    administer all its provisions, as is the case here, it is “clear” that the agency has the necessary authority to do so. See
    Gonzales, 
    546 U.S. at 258
    –59.
    No. 19-1298                        Gun Owners of Am., Inc. v. Garland                               Page 10
    concerning the application of the Final Rule to a specific factual situation. Thus, under Babbitt,
    it is clear that Chevron deference provides the standard of review, not the rule of lenity.
    My colleagues in favor of reversal suggest two other reasons why Chevron ought not to
    apply in the context of laws with criminal consequences: deferring to agency expertise may be
    warranted when interpreting civil statutes but not when agencies interpret laws with criminal
    penalties; and delegation in the criminal context violates the separation-of-powers principle. The
    arguments in support of these rationales are largely based on policy, analogy, and law review
    articles,9 but not precedent.
    There are many areas where Congress relies on agency expertise to implement laws with
    criminal applications. Just to name a few, we have highly technical and complex securities, tax,
    workplace safety, and environmental-law regimes in which the applicable agency exercises
    delegated authority to promulgate regulations fleshing out statutory provisions—regulations that
    have both civil and criminal applications. And no one contests that criminal law and procedure
    afford special protections to a criminal defendant that are not accorded to a civil defendant. But
    it does not follow that an agency’s law-interpreting power falls away in the criminal context
    where the power was properly delegated to the agency and exercised through legislative
    rulemaking.      To the extent my colleagues’ inclination to cabin agency expertise to civil
    applications is motivated more by a displeasure with Chevron’s continued validity and legislative
    delegation more broadly, Chevron is the law and legislative delegation is a reality.
    That legislative delegation is permissible undermines the separation-of-powers rationale
    as well. The Supreme Court has recognized Congress’s delegation authority in the criminal
    context for over a century. For example, in United States v. Grimaud, 
    220 U.S. 506
     (1911),
    Congress delegated to the Secretary of Agriculture the power to promulgate rules—with criminal
    penalties—to preserve certain forest reserves. 
    Id. at 507
    –09. The Secretary issued a rule
    prohibiting livestock grazing near these reserves without a permit. 
    Id. at 509
    . The defendant
    sheep farmers were indicted for violating this rule.               
    Id.
       They argued that the rule was
    9
    For an article expressing a contrary view, see Sanford N. Greenberg, Who Says It’s a Crime: Chevron
    Deference to Agency Interpretations of Regulatory Statutes That Create Criminal Liability, 58 U. PITT. L. REV. 1
    (1996), especially Section III.
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                        Page 11
    unconstitutional because Congress could not “mak[e] it an offense to violate rules and
    regulations made and promulgated by the Secretary of Agriculture,” since doing so would
    “delegate its legislative power to an administrative officer.” 
    Id. at 513
    . Although Congress had
    not declared, “in express terms,” that it was unlawful to graze sheep on a forest reserve, the
    Supreme Court rejected the challenge. See 
    id. at 521
     (rejecting the argument that the rules were
    invalid merely “because the violation thereof is punished as a public offense”).
    In the ensuing decades, several Supreme Court decisions recognized that Congress may
    delegate legislative authority in the criminal context. See, e.g., J.W. Hampton, Jr. & Co. v.
    United States, 
    276 U.S. 394
    , 406–07 (1928) (“The field of Congress involves all and many
    varieties of legislative action, and Congress has found it necessary to use officers of the
    executive branch within defined limits, to secure the exact effect intended by its acts of
    legislation, by vesting discretion in such officers to make public regulations interpreting a statute
    and directing the details of its execution, even to the extent of providing for penalizing a breach
    of such regulations.” (citing Grimaud, 
    220 U.S. at 518
    ) (other citations omitted)); Yakus v.
    United States, 
    321 U.S. 414
    , 418, 423–25 (1944) (upholding delegation of authority to agency to
    issue price-limit regulations under Emergency Price Control Act even though violating the
    regulations carried criminal penalties, and rejecting non-delegation and separation-of-powers
    challenges by criminal defendants convicted of violating those regulations); United States v.
    Mistretta, 
    488 U.S. 361
    , 371–74, 394–96 (1989) (upholding delegation of authority to
    Sentencing Commission to define criminal sentencing ranges and rejecting non-delegation and
    separation-of-powers challenges by criminal defendant).
    In Touby v. United States, 
    500 U.S. 160
    , 164–69 (1991), the Supreme Court upheld a
    delegation of legislative authority to the Attorney General (and the Attorney General to the Drug
    Enforcement Administration) to temporarily schedule substances under the Controlled
    Substances Act—a determination that carried criminal implications—and rejected arguments that
    this delegation violated the non-delegation doctrine or the separation of powers. The petitioners,
    who were convicted for manufacturing a temporarily scheduled substance, argued that because
    the delegated authority contemplated regulations with criminal sanctions, Congress was
    required to provide more specific direction than the intelligible principle normally required. 
    Id.
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                       Page 12
    at 165–66. They also argued that allowing the Attorney General to both schedule particular
    drugs and prosecute individuals for manufacturing them—rather than designating a different
    executive to temporarily schedule the substances—violated the separation-of-powers doctrine.
    
    Id. at 167
    . Finally, the petitioners claimed that the Attorney General improperly delegated his
    temporary scheduling power to the DEA. 
    Id. at 169
    . The Court rejected all three arguments. 
    Id.
    It concluded that under any standard the statute meaningfully constrains the Attorney General’s
    discretion to define criminal conduct and that the separation-of-powers doctrine was not violated.
    
    Id. at 167
    –69. Similarly, in United States v. Stevenson, 
    676 F.3d 557
    , 565 (6th Cir. 2012), we
    held that the “Attorney General was properly delegated authority by Congress to enact [a]
    substantive rule” providing that a federal sex-offender registration statute—which imposed
    criminal penalties—applied retroactively to those convicted of sex crimes prior to the statute’s
    passage.     See 
    id. at 563 n.3
     (rejecting defendants’ argument “that Congress lacked the
    constitutional authority to delegate this power to the Attorney General”).
    No one asserts that the National Firearms Act or the Gun Control Acts lacks an
    intelligible principle or that the Attorney General improperly delegated power to ATF. And to
    the extent that it is argued that Congress cannot give the Attorney General the power to
    implement a criminal statute through rulemaking and also enforce it, this is inconsistent with
    Touby. 
    500 U.S. at 167
    –68.
    In sum, the district court correctly determined that Chevron provides the standard of
    review by which to assess the Final Rule.
    II. Applying Chevron
    The Chevron framework consists of two steps. At step one, we ask whether the intent of
    Congress is clear and, if so, “that is the end of the matter; for the court, as well as the agency,
    must give effect to the unambiguously expressed intent of Congress.” Chevron, 
    467 U.S. at 842
    –43. If, on the other hand, the court determines Congress has not directly addressed the
    precise question at issue and the statute is ambiguous with respect to the issue, then, at step two,
    we ask if the agency’s interpretation is “based on a permissible construction of the statute.” 
    Id. at 843
    .
    No. 19-1298                          Gun Owners of Am., Inc. v. Garland                                  Page 13
    A. Step One
    “Machinegun” is defined in the National Firearms Act and the Gun Control Act as “any
    weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically
    more than one shot, without manual reloading, by a single function of the trigger.” 26 U.S.C.
    § 5845(b); 18 U.S.C. § 921(a)(23). The Final Rule defines “automatically” to mean “functioning
    as the result of a self-acting or self-regulating mechanism that allows the firing of multiple
    rounds through a single function of the trigger” and “single function of the trigger” to mean “a
    single pull of the trigger and analogous motions.” 83 Fed. Reg at 66,553. As a result, the Final
    Rule defines the term “machinegun” to include bump-stock-type devices. Id.
    To determine whether Congress has spoken directly to the precise question at issue—
    whether “machinegun” includes bump-stock devices—or whether the statute is silent or
    ambiguous regarding this issue, we employ traditional tools of statutory construction.10
    Chevron, 
    467 U.S. at 843 n.9
    . Beginning with the statutes themselves, neither the National
    Firearms Act nor the Gun Control Act defines “automatically” or “single function of the trigger.”
    When considering the statutory context, dictionary definitions, and everyday situations, however,
    both terms admit of more than one interpretation—that is, they are ambiguous. See All. for
    Cmty. Media v. F.C.C., 
    529 F.3d 763
    , 777 (6th Cir. 2008).
    The phrase “single function of the trigger” is capable of two readings: one favoring the
    government (the “shooter-focused” reading), the other favoring Gun Owners (the “mechanical”
    10
    The rule of lenity is a canon of construction. However, as discussed, it does not foreclose Chevron
    deference in the context of legislative rules interpreting statutes with criminal applications. Additionally, it “only
    serves as an aid for resolving an ambiguity,” meaning that it “comes into operation at the end of the process of
    construing what Congress has expressed” and only “when the ordinary canons of statutory construction have
    revealed no satisfactory construction.” Lockhart v. United States, 
    577 U.S. 347
    , 361 (2016); Callanan v. United
    States, 
    364 U.S. 587
    , 596 (1961). As such, perhaps the rule of lenity would have a role to play if a permissible
    construction of Congress’s intent could not be found by the end of the Chevron analysis. See Maracich v. Spears,
    
    570 U.S. 48
    , 76 (2013). But this is not the case here.
    My colleagues in favor of reversal suggest that Solid Waste Agency of N. Cook Cnty. v. Army Corps of
    Eng’rs stands for the proposition that the rule of lenity must be applied at the outset to determine if the statute is
    unambiguous. Solid Waste says no such thing. In fact, its only reference to the rule of lenity comes when the
    Supreme Court expressly declines to consider the argument that the rule of lenity displaces Chevron. See 
    531 U.S. 159
    , 174 n.8 (2001). It is true that the Court declined to apply Chevron, but this was because the agency’s
    interpretation of its own jurisdiction would have potentially extended beyond the outer bounds of Congress's
    Commerce Clause authority and created federalism—not fair notice—concerns. 
    Id. at 173-74
    .
    No. 19-1298                            Gun Owners of Am., Inc. v. Garland                                     Page 14
    reading). The shooter-focused reading corresponds to a single “pull” of the trigger—i.e., a single
    human action upon the trigger that initiates a rapid-fire sequence. Under this reading, a bump-
    stock-equipped rifle constitutes a machinegun because a single human action—the initial “pull”
    of the trigger—initiates a rapid firing sequence. The mechanical reading takes the phrase “single
    function of the trigger” to mean “single depression of the trigger.” Under this view, a bump-
    stock-equipped rifle is not a machinegun because each bullet fired is initiated by a separate
    depression of the trigger, albeit one generated by the weapon’s recoil. Accord Guedes, 920 F.3d
    at 29.
    Both readings are plausible. “The word ‘function’ focuses on the ‘mode of action’ . . . by
    which the trigger operates. But that definition begs the question [] whether ‘function’ requires
    our focus upon the movement of the trigger, or the movement of the trigger finger. The statute is
    silent in this regard.” Aposhian, 958 F.3d at 986 (quoting 4 OXFORD ENGLISH DICTIONARY 602
    (1933));11 see also WEBSTER’S THIRD NEW INTERNATIONAL DICTIONARY 920-21 (1967)
    (defining “function” as an “action”). Because neither reading is “unambiguously ‘compel[led]’
    by the statute, to the exclusion of the other one,” the statute “contains a ‘gap for the agency to
    fill.’” Guedes, 920 F.3d at 29–30 (quoting Chevron, 
    467 U.S. at 843, 860
    )).
    The word “automatically” is also ambiguous. The statute provides that a machinegun is a
    “weapon which shoots . . . automatically more than one shot, without manual reloading, by a
    single function of the trigger.” 26 U.S.C. § 5845(b) (emphasis added). Here, too, there are
    competing interpretations, and the text does not unambiguously foreclose either of them.
    Gun Owners argues that the phrase “automatically” must mean by itself with little or no
    direct human control and, because a shooter must exert constant pressure to cause a bump-stock-
    equipped rifle to continue firing, these devices do not create weapons that shoot automatically.
    The government argues that “automatically” means self-acting or self-regulating.                                  In the
    11
    Accord Guedes, 920 F.3d at 29 (“A mechanical perspective, for instance, might focus on the trigger’s
    release of the hammer, which causes the release of a round. From that perspective, a ‘single function of the trigger’
    yields a single round of fire when a bump-stock device moves the trigger back and forth. By contrast, from the
    perspective of the shooter’s action, the function of pulling the trigger a single time . . . yields multiple rounds of
    fire. . . . Neither of those interpretations is compelled (or foreclosed) by the term ‘function’ in ‘single function of the
    trigger.’ The word ‘function’ focuses our attention on the ‘mode of action’ . . . by which the trigger operates. But
    the text is silent on the crucial question of which perspective is relevant.” (citations omitted)).
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                           Page 15
    government’s view, a bump-stock-equipped rifle is “self-acting” in the sense that once the
    shooter establishes the conditions necessary to begin the firing process—pulling the trigger,
    placing a finger on the extension ledge, and applying pressure on the barrel-shroud or fore-stock
    with the other hand—the bump stock “eliminate[s] the need for the shooter to manually capture,
    harness, or otherwise utilize [the recoil] energy to fire additional rounds.” Final Rule, 83 Fed.
    Reg. at 66,532.
    According to dictionary definitions at the time the National Firearms Act was enacted,
    the word “automatically”—the adverbial form of the word “automatic”—means “[h]aving a
    self-acting or self-regulating mechanism that performs a required act at a predetermined point in
    an operation[.]” WEBSTER’S NEW INTERNATIONAL DICTIONARY 187 (2d ed. 1934); see also
    1 OXFORD ENGLISH DICTIONARY 574 (1933) (defining “Automatic” as “[s]elf-acting under
    conditions fixed for it, going of itself”). The focus on a “self-regulating mechanism” cuts against
    the suggestion that the word “automatically” requires complete, as opposed to partial,
    automation, and lends support to ATF’s classification. Further, the argument that bump-stock-
    equipped weapons do not fire “automatically” because they require constant forward pressure is
    belied by common usage of the word “automatic.”              For example, “an ‘automatic’ sewing
    machine still ‘requires the user to press a pedal and direct the fabric.’” Guedes, 920 F.3d at 30
    (citation omitted)). And an “automatic” car shifts gears on its own, but only if the driver
    maintains enough constant pressure on the gas pedal to reach a speed that triggers a gear shift.
    As other courts have recognized, the ultimate question is how much human input is
    contemplated by the word “automatically.” That is a question of degree that the statute’s text
    does not definitively answer. The D.C. Circuit’s explanation captures this point well:
    The term “automatically” does not require that there be no human involvement to
    give rise to “more than one shot.” Rather, the term can be read to require only
    that there be limited human involvement to bring about more than one shot. See,
    e.g., Webster’s New International Dictionary 157 (defining “automatically” as the
    adverbial form of “automatic”); id. at 156 (defining “automatic” as “self-acting or
    self-regulating,” especially applied to “machinery or devices which perform parts
    of the work formerly or usually done by hand” (emphasis added)). But how much
    human input in the “self-acting or self-regulating” mechanism is too much?
    . . . . [T]he phrase “by a single function of the trigger” . . . can naturally be read to
    establish only the preconditions for setting off the “automatic” mechanism,
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                           Page 16
    without foreclosing some further degree of manual input such as the constant
    forward pressure needed to engage the bump stock in the first instance. And if so,
    then the identified ambiguity endures. How much further input is permitted in the
    mechanism set in motion by the trigger? The statute does not say.
    Guedes, 920 F.3d at 30-31. Thus, “automatically” is also ambiguous.
    In sum, because neither party’s interpretation of either term is unambiguously compelled
    by the statute, the statutory definition of “machinegun” contains two central ambiguities, which
    ATF has attempted to resolve. This leads to step two of the analysis under Chevron.
    B. Step Two
    When employing the Chevron framework, we do not ask if the agency’s construction is
    the best reading of the statute. Id. at 843 n.11. The question is whether ATF’s interpretations of
    “single function of the trigger” and “automatically” are permissible. Mead, 
    533 U.S. at 229
    .
    Since 2006, ATF has interpreted “single function of the trigger” to mean “single pull of
    the trigger,” a reading that is “consonant with the statute and its legislative history.” Akins,
    312 F. App’x at 198. When the National Firearms Act was enacted in 1934, the president of the
    National Rifle Association testified in a congressional hearing that any gun capable of firing
    more than one shot by a single pull of the trigger was a machinegun, and the House Report
    accompanying the bill that became the National Firearms Act said the same. See H.R. Rep. No.
    73-1780, at 2 (1934); Final Rule, 83 Fed. Reg. at 66,518. Thus, ATF’s interpretation of “single
    function of the trigger” is a permissible construction. Accord Aposhian, 958 F.3d at 988;
    Guedes, 920 F.3d at 31. Further, ATF’s focus on the single human action upon the trigger is
    reasonable. The practical effect of the bump-stock device is to turn a semiautomatic firearm into
    a rapid-fire firearm that only requires the person firing the gun to pull the trigger once.
    ATF’s interpretation of “automatically” as “self-acting or self-regulating” is permissible
    as well. Although this interpretation allows for some measure of human involvement, it accords
    with the everyday understanding of the term and relevant dictionary definitions from when
    “machinegun” was first defined in 1934 by the National Firearms Act and later slightly altered in
    1968 by the Gun Control Act. For example, understanding “automatic” to allow for some human
    involvement, not complete autonomy, is commonplace. Guedes, 920 F.3d at 31; Aposhian,
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                       Page 17
    958 F.3d at 989 (“The bump stock performs part of the work usually done by hand at a
    predetermined point in the operation, under conditions fixed for it by the shooter.”).
    Additionally, Webster’s New International Dictionary defined “automatic” as “[h]aving a self-
    acting or self-regulating mechanism,” and dictionaries from 1965 and 1967 do the same.
    WEBSTER’S NEW INTERNATIONAL DICTIONARY 187 (2d ed. 1934); WEBSTER’S THIRD NEW
    INTERNATIONAL DICTIONARY 148 (1965); WEBSTER’S SEVENTH NEW COLLEGIATE DICTIONARY
    60 (1967). ATF’s interpretation of “automatically” is therefore a permissible construction.
    Accord Aposhian, 958 F.3d at 988–89; Guedes, 920 F.3d at 31–32. It is also reasonable to read
    “automatically” to require only partial self-regulation—i.e., a mechanism that allows for an
    integral part of a process to be performed autonomously. Because bump-stock-type devices
    harness the recoil energy from each shot so that the trigger resets and continues firing without
    additional physical manipulation of the trigger by the shooter, they can reasonably be understood
    to produce more than one shot, automatically.
    In sum, § 5845(b) is ambiguous and ATF’s construction of it is permissible and
    reasonable. The court must therefore defer to ATF’s interpretation.
    III. Assuming Chevron Does Not Apply
    Assuming arguendo that Chevron does not apply, the district-court judgment should still
    be affirmed. Because ATF has been entrusted to administer both the National Firearms Act and
    the Gun Control Act, and its views “constitute a body of experience and informed judgment to
    which courts . . . may properly resort for guidance,” its construction of § 5845(b) is not “outside
    the pale of any deference whatever.” Mead, 
    533 U.S. at 227
    –28, 234 (quoting Skidmore v. Swift
    Co., 
    323 U.S. 134
    , 140 (1944)). The Final Rule may warrant Skidmore deference, depending
    “upon the thoroughness evident in its consideration, the validity of its reasoning, its consistency
    with earlier and later pronouncements, and all those factors which give it power to persuade, if
    lacking power to control.” 
    Id. at 228
     (quoting Skidmore, 
    323 U.S. at 139
    –40); see also 
    id.
    (“[C]ourts have looked to the degree of the agency’s care, its consistency, formality, and relative
    expertness[.]” (footnotes omitted)).
    No. 19-1298                          Gun Owners of Am., Inc. v. Garland                                 Page 18
    In ten letter rulings issued between 2008 and 2017, ATF applied its “single pull of the
    trigger” interpretation to other bump-stock-type devices but ultimately concluded that the
    devices were not machineguns because they did not “automatically” shoot more than one shot
    with a single pull. Final Rule, 83 Fed. Reg. at 66,517. None of them, however, extensively
    examined the meaning of “automatically.” 
    Id.
     Moreover, this position was inconsistent with the
    position taken by ATF in 2006, when it concluded that one such bump-stock-type device—the
    Akins Accelerator, which allowed the shooter to initiate an automatic firing cycle by pulling the
    trigger once, thereby harnessing the recoil energy of the rifle to fire more than one shot without
    further human input by means of internal springs within the device—was a machinegun. 
    Id.
    After the 2017 mass shooting in Las Vegas, Nevada, ATF recognized that its earlier letter rulings
    failed to provide substantial or consistent legal analysis regarding the meaning of the term
    “automatically” and deviated from its 2006 position defining a bump-stock-type device as a
    machinegun,12 which the Final Rule sets out to correct. 
    Id. at 66,
    517–18.
    ATF unquestionably has abundant experience and expertise in determining which devices
    constitute machineguns. Additionally, the Final Rule went through the highly formal process of
    notice and comment. And, in promulgating the Final Rule, ATF responded to over 186,000
    comments—including one by Plaintiff Gun Owners on behalf of more than 1.5 million gun
    owners—and provided expansive reasoning for why bump stocks are machineguns,
    demonstrating a great degree of care in considering the issue. These factors—together with the
    validity of ATF’s reasoning—entitle ATF’s interpretation to at least Skidmore deference.
    Finally, ignoring all deference, ATF’s interpretation of the statute is the best one.
    According to Gun Owners and my colleagues favoring reversal, Congress meant only to prohibit
    weapons capable of firing more than one shot with a single mechanical depression of the trigger.
    12
    Although the bump-stock-type devices described in the Final Rule harness the recoil energy of a rifle
    differently than the Akins Accelerator—by means of a sliding stock that allows the weapon to slide back into the
    shooter’s shoulder after the discharge of a round and then forward into the stationary trigger finger by maintaining
    pressure on the barrel-shroud or fore-grip of the rifle, rather than internal springs—both are designed to the same
    end. They each harness a rifle’s recoil energy to produce an automatic firing cycle beginning with a single pull of
    the trigger and continuing without additional manipulation of the trigger or significant manipulation of the firearm
    by the shooter until the trigger finger is withdrawn, the weapon malfunctions, or the ammunition supply is
    exhausted. 83 Fed. Reg. at 66,517–18. The absence of significant manipulation of the firearm distinguishes the
    bump stock from the pump-action shotgun.
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                       Page 19
    This interpretation would exclude semiautomatic rifles with bump stocks attached because they
    fire only a single shot each time the trigger is depressed—notwithstanding that the trigger is
    depressed by the operation of the bump stock and the bump stock allows the shooter to fire
    semiautomatic rifles at the rapid rates of automatic weapons with one activation of the trigger.
    However, this reading neglects to account for how “automatically” and “single function of the
    trigger” work together as a practical matter, and therefore fails to give full meaning to the
    statutory definition.
    When reading the key statutory terms of “machinegun” in conjunction with each other—
    “any weapon which shoots,” “automatically more than one shot,” “by a single function of the
    trigger”—the definition refers to any weapon that is capable of discharging multiple rounds by
    means of a mechanism set in motion by a single function of the trigger. Courts have recognized
    “single function” to mean “single pull,” as this is “consonant with the statute and its legislative
    history,” Akins, 312 F. App’x at 200; and “automatically” to refer to a self-acting mechanism set
    in motion by a single pull of the trigger to discharge multiple rounds, United States v. Olofson,
    
    563 F.3d 652
    , 658 (7th Cir. 2009).            Moreover, as mentioned above, understanding
    “automatically” and “single function” to refer to, respectively, a self-regulating mechanism and a
    single human action is consistent with dictionary definitions from the relevant timeframe.
    Thus, the best interpretation of § 5845(b) is that Congress, in defining “machinegun” as it
    did, intended to prohibit weapons capable of discharging multiple rounds continuously by means
    of a self-regulating mechanism initiated by a single human input on the trigger. This is precisely
    the interpretation the Final Rule provides. And, as the Final Rule thoroughly explains, this is
    exactly how a bump stock operates: after a shooter gets into position, a single pull of the trigger
    by the shooter initiates a sequence in which the bump stock harnesses and directs the firearms’
    recoil energy so that the firearm fires continuously without additional physical manipulation of
    the trigger by the shooter or any manual reloading. 83 Fed. Reg. at 66,516.
    Thus, not only does ATF’s interpretation warrant Skidmore deference, but, in the absence
    of all deference, and simply as a matter of statutory interpretation, it also embodies the best
    reading of the statute.
    No. 19-1298                   Gun Owners of Am., Inc. v. Garland                     Page 20
    ***
    In sum, the rule of lenity is inapplicable. The Chevron framework applies to ATF’s
    legislative regulation—the Final Rule; and because the statute is ambiguous and ATF’s
    construction is permissible and reasonable, it warrants deference.       Alternatively, ATF’s
    interpretation of the statute is entitled to Skidmore deference. Finally, simply as a matter of
    statutory interpretation, the Final Rule embodies the best interpretation of the statute and
    operates to provide fair notice of that interpretation. The district court’s judgment should be
    affirmed.
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                       Page 21
    ___________________________________________________________________________
    OPINION IN SUPPORT OF AFFIRMING THE DISTRICT COURT’S JUDGMENT
    ___________________________________________________________________________
    GIBBONS, Circuit Judge, writing in support of affirming the district court judgment.
    I agree with Judge White’s assertion that Chevron applies to statutes with criminal penalties and
    her conclusion of the outcome under Chevron. I write separately, as Judge White ultimately
    concludes in the alternative, because Chevron application is unnecessary here. The ATF’s
    interpretation of “single function of the trigger” and “automatically” is unambiguously the best
    interpretation of the Gun Control Act using ordinary tools of statutory construction. Congress
    specifically prohibited “any part designed and intended solely and exclusively . . . for use in
    converting a weapon into a machinegun.” 26 U.S.C. § 5845(b). As a part designed to convert a
    semiautomatic gun into a gun with machinegun functionality that “automatically” allows for
    multiple shots with a “single function of the trigger,” a bump stock is unambiguously a
    machinegun. When a shooter pulls the trigger of a firearm fitted with a bump stock, the gun,
    through “a self-acting or self-regulating mechanism,” 
    83 Fed. Reg. 246
    , 66514, 66519 (Dec. 26,
    2018), fires “more than one shot, without manual reloading, by a single function of the trigger.”
    26 U.S.C. § 5845(b). Indeed, that is precisely what a bump stock is designed to allow a gun to
    do, and that is why people purchase bump stocks.           Holding otherwise would allow gun
    manufacturers to circumvent Congress’s longtime ban on machineguns by designing parts
    specifically intended to achieve machinegun functionality with a single pull of the trigger so long
    as the part also requires some minutia of human involvement.
    No. 19-1298                   Gun Owners of Am., Inc. v. Garland                      Page 22
    _________________
    DISSENT
    _________________
    MURPHY, Circuit Judge, dissenting. Since the early days of our Republic, it has been a
    bedrock legal principle that our government cannot criminalize conduct and send people to
    prison except through democratically passed laws that have made it through both Houses of
    Congress and been signed by the President. See United States v. Hudson, 
    11 U.S. 32
    , 34 (1812).
    Yet the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) has sought to ban “bump
    stocks” in a far different way: through a regulation adopted by a federal agency alone. Bump-
    Stock-Type Devices, 
    83 Fed. Reg. 66,514
     (Dec. 26, 2018) (“Bump-Stock Rule”). By an equally
    divided vote, our court affirms a decision rejecting a legal challenge to the ATF’s Bump-Stock
    Rule. I must respectfully dissent from this judgment. Nothing in Congress’s two relevant
    statutes delegates to the ATF such broad power to expand a crime’s scope through this sort of
    regulatory lawmaking.
    In 1986, Congress amended the Gun Control Act of 1968 to make it a crime to possess a
    “machinegun,” 18 U.S.C. § 922(o)(1), a term defined in the National Firearms Act of 1934, 26
    U.S.C. § 5845(b). Gun Owners of Am., Inc. v. Garland, 
    992 F.3d 446
    , 450–51 (6th Cir. 2021).
    For years, the ATF asserted that private parties could lawfully possess the bump stocks at issue
    in this case because these devices did not fall within Congress’s “machinegun” definition.
    Bump-Stock Rule, 83 Fed. Reg. at 66,516. So Americans bought millions of dollars’ worth of
    bump stocks. 
    Id. at 66,
    547. Then the ATF changed its position. In the Bump-Stock Rule, the
    ATF agreed that the possession of bump stocks had been lawful in the past but asserted that the
    devices would become illegal “machineguns” on the rule’s effective date. 
    Id. at 66,
    525. There
    thus can be no doubt that the Bump-Stock Rule creates a new crime.
    Judge Batchelder’s panel opinion persuasively explained that neither the Gun Control Act
    nor the National Firearms Act gives the ATF the power to expand the law banning machine guns
    through this legislative shortcut. Gun Owners, 992 F.3d at 454–74. I write to add a few more
    thoughts on why bump stocks are not “machineguns” under these laws and why we cannot fall
    back on “Chevron deference” to save the ATF’s rule. See Chevron, U.S.A., Inc. v. Nat. Res. Def.
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                       Page 23
    Council, Inc., 
    467 U.S. 837
     (1984). Many people, I suspect, would not understand why anyone
    would want to own a bump stock, a device that helps a person shoot semiautomatic rifles at rapid
    rates approaching those of automatic weapons. But this case has nothing to do with the policy
    debate over whether Congress should have banned bump stocks after the tragic Las Vegas
    shooting in 2017. Despite the introduction of multiple bills, Congress opted not to pass such
    legislation. And while the burdensome legislative process may seem “unworkable” in today’s
    polarized age, it is a core component of our separation of powers designed to protect the liberty
    of all Americans—not just bump-stock owners. INS v. Chadha, 
    462 U.S. 919
    , 959 (1983).
    Whether one favors or disfavors a policy banning bump stocks, we should all be concerned with
    the way in which the federal government has enacted that policy into law.
    I
    This case implicates administrative-law questions with significance for many statutes. At
    bottom, though, it raises a pure question of statutory interpretation: Are rifles fitted with bump
    stocks “machineguns” under the definition in 26 U.S.C. § 5845(b)? We have long described this
    type of question as “the bread and butter of the work of federal courts.” Dolfi v. Pontesso,
    
    156 F.3d 696
    , 700 (6th Cir. 1998). I do not find it particularly difficult to answer.
    The parties largely agree on the “basic” facts. U.S. Bank Nat’l Ass’n v. Vill. at Lakeridge,
    LLC, 
    138 S. Ct. 960
    , 966 (2018). Many rifles are either “automatic” or “semiautomatic.” An
    “automatic” rifle continuously fires shots with one activation of the trigger, so a shooter must
    release the trigger to stop firing. See Webster’s Ninth New Collegiate Dictionary 118 (1984);
    Webster’s New International Dictionary of the English Language 187 (2d ed. 1934) (“Webster’s
    Second”). A “semiautomatic” rifle fires only one shot with one activation of the trigger, so a
    shooter must release and reengage the trigger for each shot. See Webster’s Second, supra, at
    2274.
    Automatic weapons usually fire at greater speeds than semiautomatic weapons because
    the shooter can hold down the trigger to keep firing and need not repeatedly release and reengage
    it. See Bump-Stock Rule, 83 Fed. Reg. at 66,516. But experts can “bump fire” semiautomatic
    rifles at rates approaching those of some automatic firearms. An ATF official described bump
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                       Page 24
    firing as “rapid manual trigger manipulation to simulate automatic fire,” Letter, R.1-4, PageID
    34; the Bump-Stock Rule describes it as a “technique that any shooter can perform with training
    or with everyday items such as a rubber band or belt loop,” 83 Fed. Reg. at 66,532. A shooter
    who bump fires relies on the recoil energy from the rifle’s discharge to push the gun slightly
    backward away from the trigger finger, which remains stationary. The rifle’s trigger resets as it
    separates from the trigger finger. The shooter then uses the non-trigger hand placed on the rifle’s
    fore-end to push the gun (and thus the trigger) slightly forward. The trigger “bumps” into the
    still-stationary trigger finger, discharging a second shot. The recoil energy from each additional
    shot combined with the shooter’s forward pressure with the non-trigger hand allows the rifle’s
    backward-forward cycle to repeat itself rapidly. A shooter may also use a belt loop to bump fire
    by sticking the trigger finger inside the loop and shooting from waist level to keep the rifle more
    stable. See id. at 66,533.
    A bump stock also helps a shooter engage in rapid bump firing.               It replaces a
    semiautomatic rifle’s standard stock with one that allows the rifle to slide back and forth within
    the stock by about 1.5 inches. Id. at 66,516, 66,518. This bump stock channels the recoil energy
    from the rifle’s discharge in “constrained linear rearward and forward paths” and relieves the
    shooter of the need to “manually capture and direct” the recoil energy. Id. at 66,532. Yet a
    shooter still must use the non-trigger hand to put forward pressure on the fore-end so that the
    rifle and trigger move forward after the recoil. Id. at 66,518. When the shooter’s manual
    pressure pushes the trigger forward, it bumps into the trigger finger and discharges a second shot.
    The process repeats itself rapidly in the same general manner that it would were the shooter to
    bump fire without a bump stock. Id.
    Given these facts, a bump stock does not qualify as a “machinegun.”              26 U.S.C.
    § 5845(b); 18 U.S.C. § 921(23).      Congress defined the word to cover both a weapon that
    “shoots” “automatically more than one shot” “by a single function of the trigger” and a “part”
    that is “designed” “exclusively” “for use in converting a weapon into a machinegun”:
    The term “machinegun” means any weapon which shoots, is designed to shoot, or
    can be readily restored to shoot, automatically more than one shot, without
    manual reloading, by a single function of the trigger. The term shall also include
    the frame or receiver of any such weapon, any part designed and intended solely
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                        Page 25
    and exclusively, or combination of parts designed and intended, for use in
    converting a weapon into a machinegun, and any combination of parts from
    which a machinegun can be assembled if such parts are in the possession or under
    the control of a person.
    26 U.S.C. § 5845(b). For a bump stock to be a “machinegun” under this definition, a rifle fitted
    with that device must qualify as one. Yet such a “bump-stock rifle” does not qualify.
    To begin with, a bump-stock rifle does not shoot “more than one shot” “by a single
    function of the trigger.” A “function” of a tangible thing is the “natural and proper action” that it
    performs.   Webster’s Second, supra, at 876; American Heritage Dictionary of the English
    Language 533 (1969).        Put another way, a thing’s “function” is “the action for which
    [the] . . . thing is specially fitted or used or for which [the] thing exists[.]” Webster’s Ninth,
    supra, at 498. And putting a bump stock on a semiautomatic rifle does not change the “function”
    of its “trigger”: to discharge one round per depression. All agree that a bump-stock rifle’s trigger
    must be released and “re-engage[d]” between shots—just as occurs with ordinary bump firing.
    83 Fed. Reg. at 66,516; United States v. Alkazahg, __ M.J. __, 
    2021 WL 4058360
    , at *5 (N-M
    Ct. Crim. App. Sept. 7, 2021). The firearm thus shoots one shot per trigger function. If this
    trigger fired more than one shot per activation, a person would more naturally refer to that result
    as a “malfunction” of the trigger than a “function” of it. Cf. United States v. Olofson, 
    563 F.3d 652
    , 658–59 (7th Cir. 2009).
    Further, the discharge of more than one shot “by a single function of the trigger” does not
    alone make a firearm a “machinegun.” The firearm must also do so “automatically.” That is, it
    must operate “in a manner essentially independent of external influence or control,” American
    Heritage, supra, at 90, or in a “self-acting or self-regulating” manner, Webster’s Ninth, supra, at
    118. What type of weapon might shoot multiple shots “by a single function of the trigger” but
    not do so “automatically”? The Bump-Stock Rule gave an example. A certain pump-action
    shotgun fires multiple shots with one trigger depression if the shooter pumps the shotgun with
    the non-trigger hand to load and shoot additional shells. 83 Fed. Reg. at 66,534. Although this
    shotgun shoots more than one shot per trigger function, it does not do so “automatically” because
    the shooter must manually pump it. Id. This logic also disqualifies rifles equipped with bump
    stocks. They will fire only one shot if a shooter presses the trigger and uses no “external
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                         Page 26
    influence” with the non-trigger hand. American Heritage, supra, at 90; Aposhian v. Wilkinson,
    
    989 F.3d 890
    , 896 (10th Cir. 2021) (en banc) (Tymkovich, C.J., dissenting). To fire additional
    shots, a shooter must exert manual force so that the trigger repeatedly pushes into the trigger
    finger. Vasquez Decl., R.7, PageID 146.
    Lastly, this interpretation fits the context.       The statutory text defines the word
    “machinegun.” See Johnson v. United States, 
    559 U.S. 133
    , 140 (2010); Solid Waste Agency of
    N. Cook Cnty. v. Army Corps of Eng’rs (SWANCC), 
    531 U.S. 159
    , 171–72 (2001). And this
    interpretation matches how an “appropriately informed” user of the English language would
    distinguish a “machinegun” from an ordinary rifle. See Van Buren v. United States, 
    141 S. Ct. 1648
    , 1657 (2021) (citation omitted). A “machine gun” is typically viewed as “an automatic
    gun[.]” Webster’s Ninth, supra, at 713; Webster’s Second, supra, at 1474. And the difference
    between an “automatic” and a “semiautomatic” weapon has long turned on a mechanical feature
    of its trigger. If the gun automatically reloads and refires with one trigger activation, it is a
    machine gun. If it automatically reloads the next cartridge but requires “another pressure of the
    trigger for each successive shot,” it is a semiautomatic gun. Webster’s Ninth, supra, at 1069; see
    also id. at 118; Webster’s Second, supra, at 187, 2274. Because a bump-stock rifle’s trigger
    must be reengaged for each shot, it is not a machine gun under the ordinary understanding of that
    term. See Guedes v. Bureau of Alcohol, Tobacco, Firearms and Explosives, 
    920 F.3d 1
    , 44–45
    (D.C. Cir. 2019) (per curiam) (Henderson, J., concurring in part and dissenting in part).
    *
    The ATF’s contrary view commits two errors. It rewrites the phrase “by a single function
    of the trigger.” And it interprets the adverb “automatically” out of context.
    By a Single Function of the Trigger. Although the ATF does not dispute that a bump-
    stock rifle’s trigger must be released and reengaged for each shot, it says that the rifle shoots
    multiple shots “by a single function of the trigger.” Its logic for this head-scratching result starts
    by rewriting “single function of the trigger” to mean “single pull of the trigger.” Bump-Stock
    Rule, 83 Fed. Reg. at 66,518. From there, it says that a shooter need only “pull” the trigger once
    No. 19-1298                      Gun Owners of Am., Inc. v. Garland                          Page 27
    because additional shots result from the trigger pushing against the stationary trigger finger. 
    Id. at 66,
    519.
    This reading conflicts with basic interpretive principles. To rewrite “function” to mean
    “pull,” the ATF cites a Supreme Court footnote and a snippet of legislative history. See 
    id. at 66,
    518. It should have started with the word’s ordinary meaning. See Encino Motorcars, LLC v.
    Navarro, 
    138 S. Ct. 1134
    , 1140 (2018). Nobody would define “function” as “pull.” A thing’s
    “function” is the “action” it “is specially fitted” to perform. Webster’s Ninth, supra, at 498. The
    ATF’s use of the word “pull” wrongly changes the focus from the firearm’s mechanical
    perspective (how does the firearm work?) to the shooter’s operational perspective (how does a
    shooter shoot the gun?). Gun Owners, 992 F.3d at 470–71. Although a shooter may “pull” a
    trigger, it is unnatural to say that the shooter “functions” the trigger. But it is perfectly natural to
    say that the semiautomatic trigger properly “functions” if it shoots one shot per activation.
    The ATF’s sources do not help it. In Staples v. United States, 
    511 U.S. 600
     (1994), the
    Court distinguished automatic and semiautomatic weapons in a footnote discussing background
    facts. 
    Id. at 602 n.1
    . The decision otherwise addressed an issue not relevant here: whether the
    crime of possessing an unregistered machine gun has a mens rea element. 
    Id. at 604
    –20. This
    footnote described an automatic weapon as one that “fires repeatedly with a single pull of the
    trigger,” noting that “once its trigger is depressed, the weapon will automatically continue to fire
    until its trigger is released or the ammunition is exhausted.” 
    Id. at 602 n.1
    . Yet Staples did not
    offer a conclusive reading of the “machinegun” definition; it “merely ‘offer[ed] commonsense
    explanations’” to distinguish the weapons. Olofson, 
    563 F.3d at 658
     (citation omitted). In
    Olofson, the government itself took this view of Staples. There, the defendant read Staples as if
    it were a statute. He argued that his rifle shot only three rounds per trigger pull and so was not a
    machine gun because it did not keep shooting until the trigger was released or the ammunition
    exhausted. 
    Id. at 658
    –59. When rejecting this argument, the Seventh Circuit refused to replace
    the statute with the footnote. 
    Id. at 659
    . I would do the same.
    The ATF next turns to legislative history.           The President of the National Rifle
    Association noted that a firearm “which is capable of firing more than one shot by a single pull
    of the trigger, a single function of the trigger, is properly regarded, in my opinion, as a machine
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                       Page 28
    gun.” National Firearms Act: Hearings on H.R. 9066 Before the H. Comm. on Ways & Means,
    H.R. 9066, 73rd Cong. 40 (1934). “But legislative history is not the law.” Epic Sys. Corp. v.
    Lewis, 
    138 S. Ct. 1612
    , 1631 (2018). And the law uses the word “function.”
    Congress had good reason for this word choice. Even the ATF cannot stick with its own
    “pull” test.   It recognizes that this word might exclude from the “machinegun” definition
    weapons that repeatedly shoot with one push of a button. Bump-Stock Rule, 83 Fed. Reg. at
    66,534. So the ATF expands its interpretation of “function of the trigger” to cover not just a
    “pull” but also “analogous motions.” 
    Id.
     This change should disqualify rifles fitted with bump
    stocks. The shooter’s act of pushing the trigger into the trigger finger is an “analogous motion”
    for each shot of such a rifle. The rifle thus does not shoot multiple shots by a shooter’s single
    “pull” of or other “motion” on the trigger.
    Automatically. The ATF agrees that “automatically” means operating “as the result of a
    self-acting or self-regulating mechanism[.]”     83 Fed. Reg. at 66,519.       And, as the ATF
    recognized for a decade, shooters must use manual force with the non-trigger hand to reengage
    the trigger between each shot of a bump-stock rifle. See 
    id. at 66,
    532. But the ATF now says
    that this rifle acts “automatically” because its bump stock mechanically channels the recoil
    energy, so shooters need not “manually capture and direct recoil energy” themselves. 
    Id.
    This view reads the word “automatically” in isolation, not in context. See Johnson,
    
    559 U.S. at 139
    –40. “Automatically” does not modify the phrase “capture the recoil energy”; it
    modifies the phrase “shoots” “by a single function of the trigger.” Just because one part of a
    rifle’s operation is “automatic” does not mean that it automatically shoots by a single function of
    its trigger. Even semiautomatic rifles have some “automatic” features (hence their name). They
    use the “force of recoil and mechanical spring action to eject the empty cartridge case after the
    first shot and load the next cartridge” without human action. Webster’s Ninth, supra, at 1069.
    But they do not shoot multiple shots “automatically” “by a single function of the trigger”
    because a shooter must use manual force to reengage the trigger for each shot. The same is true
    of bump-stock rifles.
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                         Page 29
    The ATF’s reading also leaves the statute entirely unclear concerning the amount of
    human involvement necessary to distinguish a “machinegun” from an ordinary firearm. I would
    read the statute to set a rule: a gun shoots automatically by a single function of the trigger as long
    as the shooter need only manually cause the trigger to engage in a “single” function in order to
    fire multiple shots. See Guedes, 920 F.3d at 46–47 (Henderson, J., concurring in part and
    dissenting in part); Aposhian, 989 F.3d at 896 (Tymkovich, C.J., dissenting). So a typical
    machine gun qualifies even though the shooter pulls the trigger and keeps it pressed down
    because that combined external influence still does no more than result in one action of the
    trigger. I am, by contrast, at a loss over the amount of human influence that disqualifies a
    weapon as a machine gun under the ATF’s view that “function” really means “pull.” All agree
    that the shooter must exert “external influence” in addition to a single pull of the trigger.
    American Heritage, supra, at 90. So why does the bump-stock rifle shoot more automatically
    than the pump-action shotgun that also requires further human input? And why does the manual
    capturing of recoil energy render ordinary bump firing nonautomatic? The answers to these
    questions cannot be found in the amorphous law that the ATF has attempted to draft.
    The ATF lastly claims that my reading conflicts with caselaw addressing a redesigned
    semiautomatic rifle that allows a shooter to press a switch to keep the rifle firing until the release
    of the switch. ATF Supp. Br. 11–12 (citing United States v. Camp, 
    343 F.3d 743
     (5th Cir.
    2003)). But this caselaw holds only that a traditional rifle trigger need not be the “trigger” under
    § 5845(b) and that the switch can qualify as this rifle’s trigger. Camp, 
    343 F.3d at 745
    . Here,
    the ATF agrees there is just one trigger—the traditional one. A conclusion that bump stocks do
    not turn ordinary semiautomatic rifles into machine guns says nothing about whether these other
    devices qualify.
    In sum, a shooter manually reengages the trigger of a bump-stock rifle after each shot, so
    the rifle does not “automatically” shoot more than one shot “by a single function of the trigger.”
    II
    The circuit courts that have upheld the Bump-Stock Rule have not suggested that the
    ATF’s contrary view “is the better reading of the statute.” Guedes, 920 F.3d at 30. Indeed, they
    No. 19-1298                   Gun Owners of Am., Inc. v. Garland                      Page 30
    have not even felt the need to ask which is the better reading. Id. They have instead held that
    they must review the ATF’s reading under Chevron’s “two-step” approach.            Id. at 17–28;
    Aposhian v. Barr, 
    958 F.3d 969
    , 979–84 (10th Cir. 2020). At step one, these courts find that
    “automatically” and “single function of the trigger” are sufficiently ambiguous to require courts
    to defer to the ATF’s reading. Aposhian, 958 F.3d at 988–89; Guedes, 920 F.3d at 29–31. At
    step two, they hold that the ATF’s reading is “permissible.” Aposhian, 958 F.3d at 984–88;
    Guedes, 920 F.3d at 31–32.
    I find three problems with this approach. First, the courts justify their use of Chevron
    with irrelevant cases that interpret statutes expressly delegating power to an agency to enact
    criminal regulations. Second, the courts wrongly expand Chevron’s domain by holding that
    Congress impliedly delegated to the Attorney General the power to interpret a criminal law
    merely because it gave him a general authority to enact regulations.         Third, even under
    Chevron’s regime, the courts improperly find ambiguity without attempting to figure out the
    statute’s meaning.
    A. The circuit courts wrongly allow a federal agency to create a regulatory crime
    without an express delegation of criminal policymaking power from Congress.
    The circuit courts that uphold the Bump-Stock Rule justify their reliance on “Chevron
    deference” by citing cases that permit Congress to expressly delegate to an agency the power to
    create a regulatory standard backed by criminal penalties. Guedes, 920 F.3d at 24, 28 (citing
    United States v. O’Hagan, 
    521 U.S. 642
     (1997); Touby v. United States, 
    500 U.S. 160
     (1991)).
    Yet the deference that I view as “Chevron deference” traditionally arises when an agency claims
    that Congress has impliedly delegated to the agency the power to interpret the law. The use of
    this express-delegation caselaw in this case’s implied-delegation context sets a hazardous
    precedent.
    When Congress regulates private parties, it sometimes expressly gives a federal agency a
    policymaking power to adopt the governing standard of conduct. As one example, Congress told
    the Attorney General that he may add to the list of “controlled substances” that cannot be sold.
    21 U.S.C. § 811; Touby, 
    500 U.S. at 162
    –64. As another, Congress told the SEC to define the
    No. 19-1298                   Gun Owners of Am., Inc. v. Garland                      Page 31
    “acts” that are “fraudulent” during a tender offer. 15 U.S.C. § 78n(e); O’Hagan, 
    521 U.S. at 667
    .
    A party can challenge these express delegations in various ways. See United States v.
    Mead Corp., 
    533 U.S. 218
    , 227 & n.6 (2001). Most notably, Congress may not give away its
    legislative power, so these policy-laden regulations raise separation-of-powers concerns. Touby,
    
    500 U.S. at 165
    . For better or worse, however, the Supreme Court has rebuffed challenges to
    these rules under the nondelegation doctrine, even when Congress has made it a crime to violate
    them. See 
    id. at 165
    –68; United States v. Grimaud, 
    220 U.S. 506
    , 518–22 (1911); cf. Gundy v.
    United States, 
    139 S. Ct. 2116
    , 2133–48 (2019) (Gorsuch, J., dissenting).        Apart from a
    nondelegation challenge, a party might also argue that the agency’s policy choice violates the
    Administrative Procedure Act because it is procedurally arbitrary or substantively contrary to
    Congress’s instructions about the policies that the agency should adopt. See O’Hagan, 
    521 U.S. at 673
    ; 5 U.S.C. § 706(2).
    Critically, though, a party may not challenge this type of regulation on the ground that
    Congress did not give the agency the power to adopt it in the first place. Of course it did. Its
    express delegation leaves this statutory-interpretation question with an unambiguous answer.
    But that express delegation does not trigger “Chevron deference.” Cf. Cuozzo Speed Techs., LLC
    v. Lee, 
    136 S. Ct. 2131
    , 2148 (2016) (Thomas, J., concurring). Well before Chevron, the
    Supreme Court noted that it should defer to a regulation with “legislative effect” when Congress
    expressly delegated policymaking authority to the agency. Batterton v. Francis, 
    432 U.S. 416
    ,
    425 (1977); Thomas W. Merrill & Kristin E. Hickman, Chevron’s Domain, 89 Geo. L.J. 833,
    833 n.2 (2001) (collecting cases). “Chevron deference” instead comes into play when a statute
    lacks an express delegation. Chevron held that a statutory ambiguity can represent Congress’s
    “implicit” delegation to an agency to resolve the ambiguity. 
    467 U.S. at 844
    ; King v. Burwell,
    
    576 U.S. 473
    , 485 (2015). And it distinguished laws with these implicit delegations from those
    that “explicitly left a gap for the agency to fill[.]” 
    467 U.S. at 843
    –44 & 844 n.12; see Mead,
    
    533 U.S. at 229
    .
    These express-delegation cases thus are irrelevant to whether the Gun Control Act and
    the National Firearms Act contain implied delegations to the Attorney General. (The Acts
    No. 19-1298                       Gun Owners of Am., Inc. v. Garland                        Page 32
    identify the Attorney General as the enforcing official, and he has designated the ATF to act on
    his behalf. 28 C.F.R. § 0.130(a)(1)–(2).) Unlike in O’Hagan (in which Congress gave the SEC
    the power to define “fraudulent” acts), these Acts do not expressly give the Attorney General the
    power to define “machinegun.” And unlike in Touby (in which Congress gave the Attorney
    General the ability to add to the list of “controlled substances”), the Acts do not expressly give
    the Attorney General the ability to add to a list of “machineguns.” Congress instead defined
    “machinegun” itself.
    *
    If anything, the use of this express-delegation precedent in Chevron’s implied-delegation
    context marks a sharp break from past practice. The cases allowing agencies to create criminal
    regulations come with an important safeguard: Congress itself must “make[] the violation of
    regulations a criminal offense and fix[] the punishment[.]” Loving v. United States, 
    517 U.S. 748
    , 768 (1996). So when a statute left unclear whether Congress gave an agency the power to
    create regulatory crimes, the Supreme Court refused to interpret the statute as granting this
    power.      See United States v. Eaton, 
    144 U.S. 677
    , 687–88 (1892).              Congress must act
    “distinctly”—i.e., clearly—if it wants to allow agencies to enact criminal rules with the force of
    law. 
    Id. at 688
    ; Grimaud, 
    220 U.S. at 519
    . This clear-statement rule established a presumption
    against “which Congress legislates” well before Chevron. Singer v. United States, 
    323 U.S. 338
    ,
    350–51 (1945) (Frankfurter, J., dissenting); Thomas W. Merrill & Kathryn Tongue Watts,
    Agency Rules with the Force of Law: The Original Convention, 116 Harv. L. Rev. 467, 499–502
    (2002).     The statute in O’Hagan, for example, expressly made it a crime to violate “any
    provision of this chapter” or “any rule or regulation thereunder the violation of which is made
    unlawful or the observance of which is required under the terms of this chapter[.]” 15 U.S.C.
    § 78ff(a); O’Hagan, 
    521 U.S. at 677 n.23
    .
    The clear-statement rule is “not a judicial sport.” Singer, 
    323 U.S. at 350
     (Frankfurter, J.,
    dissenting). It reinforces a fundamental separation-of-powers principle. Carter v. Welles-Bowen
    Realty, Inc., 
    736 F.3d 722
    , 733 (6th Cir. 2013) (Sutton, J., concurring). The Constitution allows
    only Congress to create crimes. See United States v. George, 
    228 U.S. 14
    , 22 (1913). The
    Supreme Court cannot create common-law crimes, Hudson, 
    11 U.S. at 34,
     and the President
    No. 19-1298                      Gun Owners of Am., Inc. v. Garland                        Page 33
    cannot create administrative crimes, George, 
    228 U.S. at 22
    . This principle promotes liberty by
    barring the government from forcing Americans to change their behavior on threat of
    imprisonment unless their representatives pass a bill that survives the arduous journey through
    both Houses of Congress and their President signs this bill into law. See Bond v. United States,
    
    564 U.S. 211
    , 222 (2011).
    The circuit courts that use the express-delegation precedent to invoke Chevron flout this
    clear-statement rule and the separation-of-powers principle that it protects. The Bump-Stock
    Rule creates a new regulatory crime that bars the possession of bump stocks. Yet it does so
    allegedly pursuant to only an implied (not a distinct) congressional delegation of power.
    The courts all agree that the Bump-Stock Rule purports to be a legislative rule that
    creates a new crime with the “force and effect of law”; it does not claim to be an interpretive rule
    that merely construes the “machinegun” ban in 18 U.S.C. § 922(o)(1).            See, e.g., Guedes,
    920 F.3d at 18 (citation omitted). The crime’s effective date shows as much. For a decade
    before the Bump-Stock Rule, the ATF issued advisory letters indicating that the bump stocks at
    issue here are not machine guns. Bump-Stock Rule, 83 Fed. Reg. at 66,516. Its position
    nurtured the creation of an entire bump-stock industry, complete with manufacturers, retailers,
    and consumers. Id. at 66,545–48. By the time of the Bump-Stock Rule, consumers had bought
    some $100 million worth of bump stocks.           Id. at 66,515.   If this rule merely interpreted
    § 922(o)(1)’s “machinegun” ban, the people who owned bump stocks during this time would all
    along have been committing felonies (on the ATF’s advice). See 18 U.S.C. § 924(a)(2). Yet the
    ATF did not seek to throw these bump-stock owners into prison. The Bump-Stock Rule instead
    purports to criminalize behavior that was previously lawful: “Anyone currently in possession of a
    bump-stock-type device is not acting unlawfully unless they fail to relinquish or destroy their
    device after the effective date of this regulation.” 83 Fed. Reg. at 66,523; see also id. at 66,525,
    66,530.
    To enact this new regulatory crime, the ATF (the Attorney General’s designee) must
    identify a statutory provision “distinctly” empowering the Attorney General to do so. Eaton,
    
    144 U.S. at 688
    . But the ATF points to no such provision. That is why the circuit courts must
    rely on Chevron. Chevron deference applies when Congress “implicitly” delegates to an agency
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                      Page 34
    the power to interpret a statute. 
    467 U.S. at 843
    –44. But an implicit delegation is not a distinct
    one. Carter, 736 F.3d at 733 (Sutton, J., concurring). Under traditional principles, then, the
    ATF lacks the power to make criminal what was lawful. And reliance on Chevron throws
    overboard what has long been a critical check on an agency’s ability to enact criminal rules:
    Such rules “must have clear legislative basis.” George, 
    228 U.S. at 22
    ; cf. Whitman v. United
    States, 
    574 U.S. 1003
    , 1004 (2014) (Scalia, J., respecting the denial of certiorari). The Bump-
    Stock Rule does not.
    To be sure, Congress gave the Attorney General the general power to issue “such rules
    and regulations as are necessary to carry out the provisions” of the Gun Control Act. 18 U.S.C.
    § 926(a). And it gave the Attorney General the general power to “prescribe all needful rules and
    regulations for the enforcement of” the National Firearms Act.           26 U.S.C. §§ 7805(a),
    7801(a)(2)(A)(i). But these grants of general rulemaking power (which exist in most statutes)
    are not express delegations of power to adopt substantive criminal rules like those in O’Hagan
    and Touby. To the contrary, a grant of general rulemaking authority can show only Congress’s
    implied delegation to an agency to resolve ambiguities under Chevron. See Mayo Found. for
    Med. Educ. & Rsch. v. United States, 
    562 U.S. 44
    , 57 (2011). The law in Chevron itself allowed
    the EPA administrator to “prescribe such regulations as are necessary to carry out his functions
    under this chapter.” 42 U.S.C. § 7601(a)(1). An assertion that the Attorney General’s general
    rulemaking power also qualified as an express delegation to establish regulatory crimes with the
    force of law would swallow Chevron’s distinction between express and implied delegations. See
    
    467 U.S. at 843
    –44.     Because these grants of rulemaking power do not “distinctly” show
    Congress’s intent to allow the Attorney General to create a new crime (as the Bump-Stock Rule
    purports to do), they do not satisfy the clear-statement rule. Eaton, 
    144 U.S. at 688
    ; cf. George,
    
    228 U.S. at 20
    –21, 20 n.†.
    Further, no other provision gives the Attorney General the power to issue a criminal rule
    implementing the Gun Control Act’s “machinegun” ban, 18 U.S.C. § 922(o)(1), or the
    “machinegun” definition that it incorporates from the National Firearms Act, id. § 921(a)(23);
    26 U.S.C. § 5845(b). This omission is telling. When the Gun Control Act permits the Attorney
    General to enact rules backed by criminal sanctions, it says so expressly. Section 923, for
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                       Page 35
    example, requires licensed firearms distributors to keep such records “as the Attorney General
    may by regulations prescribe” and makes it a misdemeanor for licensees to violate its
    recordkeeping provisions “or the regulations promulgated thereunder.”                  18 U.S.C.
    §§ 922(m), 924(a)(3)(B). Yet the Act otherwise “contains no power authorizing [the Attorney
    General] to promulgate criminal regulations,” such as regulations implementing § 922(o)(1)’s
    “machinegun” ban. Stephen P. Halbrook, Firearms Law Deskbook § 4:6, Westlaw (database
    updated Oct. 2021). Likewise, the National Firearms Act authorizes the Attorney General to
    issue regulations about, for example, licensing or registration requirements.          26 U.S.C.
    §§ 5812(a), 5822, 5841(c), 5842–44; see also id. §§ 5851(b), 5852(f), 5853(c), 5854. The Act
    also makes a violation of its own “provisions” a crime. Id. §§ 5861, 5871. But nothing in it
    allows the Attorney General to issue a legislative rule that changes the scope of its “machinegun”
    definition. Under normal interpretive principles, we should view the express inclusions and
    omissions of regulatory authority as intentional legislative choices. See Gonzales v. Oregon,
    
    546 U.S. 243
    , 262–63 (2006); Russello v. United States, 
    464 U.S. 16
    , 23 (1983); Merrill
    & Watts, supra, at 471–72, 487.
    One last point. For those persuaded by such things, the Gun Control Act’s original
    drafters discarded a provision that would have given the Attorney General the power to adopt
    legislative rules backed by criminal sanctions. One version of the Act would have broadly
    attached criminal penalties to a violation of any rule or regulation promulgated under the Act.
    See S. 917, 90th Cong. § 924(a) (as reported by Senator McClellan, Apr. 29, 1968). But Senator
    Griffin of Michigan led the charge in opposition to this language, explaining that “if there is one
    area in which we should not delegate our legislative power, it is in the area of criminal law.”
    114 Cong. Rec. 14,792 (1968). Senator Baker of Tennessee also explained how problematic it
    would be to allow a future administration to “change or alter a rule or a regulation” that is
    criminal “and thus place in the hands of an executive branch administrative official the authority
    to fashion and shape a criminal offense to his own personal liking[.]” Id. These senators
    successfully persuaded Congress to omit this “rules or regulations” catchall from what is today
    the penalty section in 18 U.S.C. § 924(a). See id. at 14,793. We disrespect its choice if we
    uphold a regulation like the Bump-Stock Rule that purports to create a new regulatory felony that
    did not exist before.
    No. 19-1298                   Gun Owners of Am., Inc. v. Garland                      Page 36
    B. The circuit courts wrongly find in a generic grant of rulemaking authority an
    implied delegation permitting an agency to authoritatively interpret criminal
    laws.
    Apart from their disregard of the clear-statement rule that predates Chevron, the circuit
    courts that uphold the Bump-Stock Rule wrongly rely on Chevron’s implied-delegation
    presumption even on that case’s own terms. They apply its presumption solely because (1) the
    Attorney General has general rulemaking power under the Gun Control Act and the National
    Firearms Act, 18 U.S.C. § 926(a); 26 U.S.C. § 7805(a), and (2) the ATF (the Attorney General’s
    designee) issued the Bump-Stock Rule under that power. See Aposhian, 958 F.3d at 979–81.
    I disagree. While a generic rulemaking provision might sometimes show an implied delegation
    that allows an agency to resolve a statutory ambiguity through a regulation, Mayo, 
    562 U.S. at 57,
     such a provision does not always do so. And it falls well short of showing an implied
    delegation here.
    Start with some background. Before Chevron, the Supreme Court applied a totality-of-
    the-circumstances test “on a statute-by-statute basis” to decide whether a statute impliedly
    delegated power to an agency to interpret an ambiguous provision. Antonin Scalia, Judicial
    Deference to Administrative Interpretations of Law, 1989 Duke L.J. 511, 516; Stephen Breyer,
    Judicial Review of Questions of Law and Policy, 38 Admin. L. Rev. 363, 365–72 (1986).
    Chevron might have been read to dramatically depart from this approach. Some viewed it as
    creating a broad rule that Congress impliedly delegated to agencies the power to resolve all
    ambiguous provisions across all statutes. Scalia, supra, at 516; cf. City of Arlington v. FCC,
    
    569 U.S. 290
    , 296 (2013).
    Yet the Court has not adopted that absolutist view. Rather, before proceeding through
    Chevron’s two-step test, it has repeatedly conducted a threshold inquiry (what some have labeled
    Chevron “step zero”) that requires us to ask whether the specific statute at issue leaves the
    specific interpretive question for the agency or the courts to resolve. Merrill & Hickman, supra,
    at 836, 873–89.    As the Court has noted, “different statutes present different reasons for
    considering respect for the exercise of administrative authority or deference to it.”     Mead,
    
    533 U.S. at 238
    . The Court thus will reject Chevron deference when a law is best read not to
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                        Page 37
    give the agency the power to resolve a particular question of statutory interpretation. That is true
    even if (as in this case) the agency issued a regulation answering that question pursuant to its
    general rulemaking authority.
    Two examples prove my point. The Court has rejected Chevron’s implied-delegation
    presumption for “major questions” about a statute. See King, 576 U.S. at 485–86; FDA v. Brown
    & Williamson Tobacco Corp., 
    529 U.S. 120
    , 159–60 (2000). “In extraordinary cases” involving
    important questions, it has noted, “there may be reason to hesitate before concluding that
    Congress has intended such an implicit delegation.” Brown & Williamson, 
    529 U.S. at 159
    (citing Breyer, supra, at 370). Take King. It addressed whether the Affordable Care Act allowed
    individuals who bought health insurance on federal exchanges to obtain tax subsidies. 576 U.S.
    at 479. The agency issued a regulation answering this question under a grant of rulemaking
    authority. Id. at 483. Yet the Court refused to give Chevron deference to this regulation. Id. at
    485–86.    The Court reasoned that the question was of “deep ‘economic and political
    significance,’” so it presumed that Congress would not have impliedly given the agency the
    power to resolve it. Id. at 486 (citation omitted).
    The Court has also rejected Chevron deference for statutory issues that have traditionally
    fallen within the courts’ interpretive domain. See Adams Fruit Co. v. Barrett, 
    494 U.S. 638
    , 649
    (1990); see also Smith v. Berryhill, 
    139 S. Ct. 1765
    , 1778–79 (2019); Epic, 
    138 S. Ct. at 1629
    .
    Take Adams Fruit. There, the agency issued a regulation under its rulemaking authority that
    narrowly interpreted a cause of action allowing private parties to sue. 
    494 U.S. at 649
    . The
    Court held that Chevron deference did not apply to this interpretation because “the scope of the
    judicial power vested by the statute” was for the courts, not the agency, to decide. 
    Id. at 650
    .
    Identical logic extends to the criminal laws, so these decisions make this case easy at
    Chevron’s threshold step. The Gun Control Act bans “machineguns” and imposes a potential
    10-year prison sentence for violations. 18 U.S.C. §§ 922(o)(1), 924(a)(2). I would not interpret
    Congress’s grant of rulemaking authority in the Gun Control Act (18 U.S.C. § 926(a)) or the
    National Firearms Act (26 U.S.C. § 7805(a)) as impliedly delegating to the Attorney General the
    “extraordinary authority” to invent new gun crimes. Gonzales, 
    546 U.S. at 262
    . Even more so
    than the cause of action in Adams Fruit, “criminal laws are for courts, not for the Government, to
    No. 19-1298                   Gun Owners of Am., Inc. v. Garland                      Page 38
    construe.” Abramski v. United States, 
    573 U.S. 169
    , 191 (2014). Whatever the merits of
    Chevron’s implied-delegation presumption in the civil context, even a Chevron proponent calls it
    “preposterous” “to say that when criminal statutes are ambiguous, the Department of Justice is
    permitted to construe them as it sees fit[.]” Cass R. Sunstein, Chevron Step Zero, 92 Va. L. Rev.
    187, 210 (2006).      Two of our foundational principles—the separation of powers and due
    process—should lead us to adopt the opposite presumption.         Congress does not impliedly
    delegate to the Attorney General our duty to interpret the criminal laws. See Gun Owners,
    992 F.3d at 464–68.
    As an initial matter, a presumption that Congress impliedly gave the Attorney General the
    power to interpret the criminal laws would further undercut our separation of powers. The
    Constitution ensures that the government cannot imprison a person without a consensus from all
    three branches. See Gun Owners, 992 F.3d at 464; Caleb Nelson, Adjudication in the Political
    Branches, 107 Colum. L. Rev. 559, 561 (2007). Congress must enact a criminal law, the
    Attorney General must initiate a prosecution, and a court must adjudicate the case.          The
    clear-statement rule that I have already discussed ensures that the Attorney General does not
    usurp Congress’s role in this process—to enact criminal bans. George, 
    228 U.S. at 22
    . We
    should likewise adhere to canons of interpretation that ensure that the Attorney General does not
    usurp the judiciary’s role—to say what the criminal laws mean. Marbury v. Madison, 
    5 U.S. 137
    , 177 (1803). Yet Chevron’s presumption that agencies get to construe ambiguous laws
    would allow the Attorney General to do just that by combining the prosecutorial and adjudicative
    powers. See Sunstein, supra, at 210.
    Admittedly, it is our duty to say what civil laws mean too. But there would be nothing
    unusual about refusing to extend Chevron’s civil presumption to this criminal setting. Criminal
    laws have the most serious repercussions for individuals, potentially depriving them of their
    liberty or lives. See United States v. Bass, 
    404 U.S. 336
    , 348 (1971). So our legal traditions
    include many safeguards unique to that context. To name two, prosecutors must prove their case
    beyond a reasonable doubt (rather than by a preponderance of the evidence), see In re Winship,
    
    397 U.S. 358
    , 361–64 (1970), and they cannot force defendants to testify when their testimony
    might subject them to criminal (as opposed to civil) liability, see United States v. Balsys,
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                         Page 39
    
    524 U.S. 666
    , 671–72 (1998). Notably, therefore, the Supreme Court has not incorporated other
    civil principles that are in tension with the separation of powers into the criminal domain.
    Although agencies may engage in fact-finding in some civil proceedings subject to deferential
    judicial review, Atlas Roofing Co. v. Occupational Safety & Health Rev. Comm’n, 
    430 U.S. 442
    ,
    455 & n.13 (1977), this agency fact-finding power falls away in “criminal matters,” N. Pipeline
    Constr. Co. v. Marathon Pipe Line Co., 
    458 U.S. 50
    , 70 n.24 (1982) (plurality opinion); Nelson,
    supra, at 610. The same logic should apply here. Chevron sometimes allows agencies to
    interpret ambiguities in civil statutes subject to deferential judicial review. See City of Arlington,
    569 U.S. at 296. Yet an agency’s law-interpreting power should likewise fall away in criminal
    matters. See Esquivel-Quintana v. Lynch, 
    810 F.3d 1019
    , 1030 (6th Cir. 2016) (Sutton, J.,
    concurring in part and dissenting in part), rev’d sub nom. Esquivel-Quintana v. Sessions,
    
    137 S. Ct. 1562
     (2017).
    In addition, Chevron’s presumption that Congress impliedly gave the Attorney General
    the power to interpret the criminal laws conflicts with a preexisting due-process presumption that
    has long affected the courts’ interpretation of those laws. See United States v. Davis, 
    139 S. Ct. 2319
    , 2325 (2019). Courts presume that Congress means for criminal laws to give ordinary
    people “fair warning” of the conduct that the laws proscribe. McBoyle v. United States, 
    283 U.S. 25
    , 27 (1931). When faced with the task of choosing between two plausible “readings of what
    conduct Congress has made a crime,” then, a court will reject the “harsher alternative” in favor
    of the more lenient one. Jones v. United States, 
    529 U.S. 848
    , 858 (2000) (quoting United States
    v. Universal C.I.T. Credit Corp., 
    344 U.S. 218
    , 221–22 (1952)). Unlike Chevron, this rule of
    lenity “is perhaps not much less old than construction itself.” United States v. Wiltberger,
    
    18 U.S. 76
    , 95 (1820). The rule allows parties to organize their affairs confident that they can
    rely on the existing law until their elected representatives change it through the legislative
    process. See Bass, 
    404 U.S. at 348
    .
    Chevron’s implied-delegation presumption (which dates to 1984) conflicts with this fair-
    notice presumption (which dates to the Founding). For one thing, it would require us to presume
    that Congress meant to give the Attorney General the power to expand the scope of an
    ambiguous criminal law by adopting the “harsher alternative” without the “clear and definite”
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                        Page 40
    statement that we usually expect. Jones, 
    529 U.S. at 858
     (citation omitted). It thus “would turn
    the normal construction of criminal statutes upside-down, replacing the doctrine of lenity with a
    doctrine of severity.” Crandon v. United States, 
    494 U.S. 152
    , 178 (1990) (Scalia, J., concurring
    in the judgment).    For another, it would allow an agency to depart from its longstanding
    interpretation of a criminal law merely for policy reasons associated with a change in presidential
    administrations and merely by going through the notice-and-comment process. See Nat’l Cable
    & Telecomms. Ass’n v. Brand X Internet Servs., 
    545 U.S. 967
    , 981–82 (2005). Such a policy-
    laden expansion of the scope of prohibited conduct has no place in this criminal sphere.
    “[A] criminal conviction ought not to rest upon an interpretation reached by the use of policy
    judgments rather than by the inexorable command of relevant language.” M. Kraus & Bros., Inc.
    v. United States, 
    327 U.S. 614
    , 626 (1946).
    Lastly, imagine what it would mean if, as the D.C. Circuit found, the Attorney General’s
    general rulemaking authority in 18 U.S.C. § 926(a) allows him to issue authoritative
    interpretations of the many crimes in § 922. See Guedes, 920 F.3d at 26. The Supreme Court
    recently interpreted the statute banning the possession of firearms by felons to require defendants
    to know that they are, in fact, felons. See Rehaif v. United States, 
    139 S. Ct. 2191
    , 2194 (2019);
    18 U.S.C. §§ 922(g), 924(a)(2). Suppose that the Attorney General later issues a regulation
    readopting the view long held by all of the circuit courts that the statute lacked this intent
    element. Rehaif, 139 S. Ct. at 2201 (Alito, J., dissenting). If Rehaif is best read as endorsing one
    side of a debate about an ambiguous statute, would the Court have to defer to the Attorney
    General’s regulation and return the criminal law back to a world without this mens rea? See
    Brand X, 
    545 U.S. at 982
    –83; cf. United States v. Home Concrete & Supply, LLC, 
    566 U.S. 478
    ,
    487–90 (2012) (plurality opinion).
    Courts have also struggled to interpret the Armed Career Criminal Act, which imposes an
    enhanced sentence on those who illegally possess firearms and have three prior “violent felony”
    convictions. 18 U.S.C. § 924(e); see, e.g., Borden v. United States, 
    141 S. Ct. 1817
    , 1821 (2021)
    (plurality opinion). Perhaps this was all just wasted effort. If § 926(a) gives the Attorney
    General the power to issue a binding regulation listing every offense that qualifies as a “violent
    felony,” must courts defer to the Attorney General’s view? I doubt any judge would take these
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                      Page 41
    claims seriously. But they are no different from the claim that Chevron applies in this case
    simply because § 926(a) gives the Attorney General general rulemaking authority.
    In sum, the generic grants of rulemaking power on which other circuit courts have relied
    do not provide the “clear indication” that courts should demand before construing a criminal law
    to delegate our interpretive authority to the Attorney General. SWANCC, 
    531 U.S. at 172
    .
    *
    The circuit courts that take the opposite view suggest that Babbitt v. Sweet Home Chapter
    of Communities for a Great Oregon, 
    515 U.S. 687
     (1995), supports their conclusion that a grant
    of general rulemaking authority can trigger Chevron deference for criminal laws. See Aposhian,
    958 F.3d at 982–83; Guedes, 920 F.3d at 24. Babbitt addressed provisions of the Endangered
    Species Act that made it unlawful for a party to “take” an endangered species and imposed
    criminal and civil penalties for violations of this ban. 
    515 U.S. at 690
    –91, 696 n.9 (quoting
    16 U.S.C. §§ 1538(a)(1)(B), 1540(a)(1), 1540(b)(1)). The statute itself defined the word “take”
    to include “harm,” and the Secretary of the Interior issued a regulation broadly interpreting the
    word “harm.” Id. at 691. When rejecting the claim that this regulation misread the statute, the
    Court gave deference to the Secretary’s reading despite its criminal applications. Id. at 703–04,
    704 n.18.
    Yet Babbitt confirms that Chevron’s implied-delegation presumption does not apply here.
    While Babbitt cited Chevron in passing, it did not “rest on Chevron’s fiction that ambiguity in a
    statutory term is best construed as an implicit delegation of power to an administrative agency to
    determine the bounds of the law.” Cuozzo, 136 S. Ct. at 2148 (Thomas, J., concurring). Rather,
    Babbitt is better read as an express-delegation case. The Court noted that the Secretary’s
    regulation was entitled to “some degree of deference” not because the “take” definition was
    ambiguous (and so subject to Chevron’s presumption), but because of the “latitude” that the Act
    gave “the Secretary in enforcing the statute[.]” Babbitt, 
    515 U.S. at 703
    –04. As its support for
    this sentence, Babbitt even cited an article by Justice Breyer criticizing an implied-delegation
    presumption as “seriously overbroad, counterproductive and sometimes senseless.” Breyer,
    supra, at 373; Sunstein, supra, at 239–40. Notably, moreover, Secretary Babbitt’s enforcement
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                      Page 42
    “latitude” consisted of far more authority than the generic power to issue regulations. Most
    relevantly, the Act authorized civil and criminal penalties against those who violated “any
    regulation issued in order to implement” the “take” prohibition. Compare 16 U.S.C. § 1540(f),
    with id. § 1540(a)(1) and (b)(1). Congress thus expressly gave the Secretary the power to issue
    regulations to “implement” that specific ban and expressly made a violation of those regulations
    a crime. Id. § 1540(b)(1). This unambiguous delegation to enact criminal legislative rules that
    implement the “take” provision cannot be described as an “implicit” delegation. It would meet
    even Eaton’s clear-statement rule.
    In this case, by contrast, the Bump-Stock Rule attempts to “rest on Chevron’s fiction” by
    suggesting that Congress “implicitly left” to the Attorney General the power to interpret the
    “machinegun” definition. Cuozzo, 136 S. Ct. at 2148 (Thomas, J., concurring); Bump-Stock
    Rule, 83 Fed. Reg. at 66,527. Unlike the Endangered Species Act in Babbitt, however, the Gun
    Control Act and the National Firearms Act do not delegate to the Attorney General the specific
    power to issue regulations to “implement” the “machinegun” ban in 18 U.S.C. § 922(o)(1) or
    expressly make a violation of those implementing regulations a crime. That is why the courts
    that have upheld the Bump-Stock Rule rely only on the grants of general rulemaking authority in
    those Acts. See Guedes, 920 F.3d at 20–21. But those grants are not express delegations to pass
    criminal rules, and the enforcement “latitude” that Babbitt found important is absent here.
    
    515 U.S. at 703
    –04.
    I disagree with the other circuit courts’ competing interpretation of Babbitt. These courts
    have read that decision as instead holding that—while Chevron’s implied-delegation
    presumption does not apply for pure criminal laws—it can apply when a law has “both civil and
    criminal implications.” Aposhian, 958 F.3d at 982–83. This case shows that any distinction
    between “pure” criminal laws and “hybrid” criminal-civil laws is a mirage. If the Court reads
    Babbitt as triggering Chevron’s presumption, it will reach nearly all criminal laws.
    To begin with, although the “take” regulation in the Endangered Species Act has many
    civil applications, see, e.g., 16 U.S.C. § 1540(g), the Bump-Stock Rule has “predominately
    criminal” ones, Aposhian, 989 F.3d at 905 (Eid, J., dissenting). The Gun Control Act makes it a
    crime to possess machine guns except those transferred or possessed under the authority of a
    No. 19-1298                     Gun Owners of Am., Inc. v. Garland                    Page 43
    government or those possessed before 1986. 18 U.S.C. § 922(o). No bump stocks existed in
    1986, so the grandfather provision does not apply. Bump-Stock Rule, 83 Fed. Reg. at 66,535.
    And I doubt many governments supply their agents with bump-stock rifles. So if the Bump-
    Stock Rule’s potentially small number of civil applications triggers Chevron’s implied-
    delegation presumption, most criminal laws will trigger it too. After all, “[s]ince the earliest
    years of this Nation, Congress has authorized the Government to seek parallel in rem civil
    forfeiture actions and criminal prosecutions based upon the same underlying events.” United
    States v. Ursery, 
    518 U.S. 267
    , 274 (1996). Today, many laws include civil-forfeiture provisions
    that accompany their criminal bans. The Gun Control Act, for example, authorizes the Attorney
    General to seek forfeiture of weapons for most violations of its prohibitions. See 18 U.S.C.
    § 924(d)(1). Would this forfeiture provision trigger Chevron’s presumption for, say, a regulation
    issued by the Attorney General interpreting the prohibition on possessing a firearm in
    furtherance of a “crime of violence”? Id. § 924(c)(1)(A).
    In addition, Babbitt emphasized that the “take” regulation had “existed for two decades”
    largely unchanged from near the time of the Act’s passage and so had provided “a fair warning
    of its consequences.” 
    515 U.S. at 690, 691 n.2, 704 n.18
    . Giving some deference to this
    regulation, 
    id. at 703,
     comports with the respect that courts have shown “longstanding and
    contemporaneous executive interpretations of law[.]” Aditya Bamzai, The Origins of Judicial
    Deference to Executive Interpretation, 126 Yale L.J. 908, 916 (2017) (emphasis omitted). The
    same cannot be said for a decision to apply Chevron’s presumption here because the Bump-
    Stock Rule departed from the ATF’s decade-long view. 83 Fed. Reg. at 66,516. The Americans
    who invested in the bump-stock industry in reliance on that prior position might be skeptical of
    the claim that the ATF offered them a “fair” warning. Babbitt, 
    515 U.S. at 704 n.18
    ; cf. EEOC v.
    Arabian Am. Oil Co., 
    499 U.S. 244
    , 257–58 (1991). This case thus shows that if Chevron
    extends to the criminal context, it would extend in full. The Attorney General could change the
    criminal laws for pure policy reasons. See Brand X, 
    545 U.S. at 981
    –82. Babbitt should not be
    read to require these results.
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                     Page 44
    C. The circuit courts do not attempt to construe the statutory “machinegun”
    definition using traditional canons of construction before deferring to the
    ATF’s view.
    Even if Chevron’s two-step test applied, the circuit courts that have upheld the Bump-
    Stock Rule wrongly find ambiguity in the “machinegun” definition at step one without even
    attempting to interpret the statute themselves. See Aposhian, 958 F.3d at 979–81; Guedes,
    920 F.3d at 20–21. Chevron does not require such judicial obsequiousness to a federal agency.
    At Chevron step one, a court must ask whether the relevant statutory text is “ambiguous
    with respect to the specific issue” before the court. 
    467 U.S. at 843
    . If the text conveys an
    “unambiguously expressed” meaning, the court must apply it as written. Id.; see, e.g., MCI
    Telecomms. Corp. v. Am. Tel. & Tel. Co., 
    512 U.S. 218
    , 225–29 (1994). If the text conveys no
    unambiguous answer, the court must proceed to Chevron’s second step by asking whether the
    agency’s reading reasonably resolves the ambiguity. 
    467 U.S. at 843
    ; see, e.g., Brand X, 
    545 U.S. at 989
    –97. Like the rule of lenity, however, Chevron “leaves open the crucial question—
    almost invariably present—of how much ambiguousness constitutes an ambiguity.” United
    States v. Hansen, 
    772 F.2d 940
    , 948 (D.C. Cir. 1985) (Scalia, J.).
    Both the Supreme Court and our court have explained how to answer this crucial
    ambiguity question. A finding of ambiguity can occur only at the end of our usual interpretive
    process. In other words, a court must do its “best to determine the statute’s meaning before
    giving up, finding ambiguity, and deferring to the agency.” Arangure v. Whitaker, 
    911 F.3d 333
    ,
    338 (6th Cir. 2018). When engaging in this ordinary interpretive process, the court should
    employ the “traditional tools of statutory construction” that it would otherwise rely on when
    reviewing a statutory provision without agency input.        Epic, 138 S. Ct. at 1630 (quoting
    Chevron, 
    467 U.S. at 843 n.9
    ); see Kisor v. Wilkie, 
    139 S. Ct. 2400
    , 2415 (2019). So a court
    must give the relevant words their ordinary meaning. See MCI Telecomms., 
    512 U.S. at 225
    –28.
    If a word is susceptible to more than one meaning, the court must place it in its context and
    consider it within the statutory structure as a whole. See Pereira v. Sessions, 
    138 S. Ct. 2105
    ,
    2113, 2114–15, 2117 (2018); Esquivel-Quintana, 
    137 S. Ct. at 1570, 1572
    . Similarly, the court
    must account for the many canons of construction that routinely offer clues on the meaning of an
    No. 19-1298                       Gun Owners of Am., Inc. v. Garland                       Page 45
    ambiguous text. Arangure, 911 F.3d at 339–40 (collecting cases). The Supreme Court, for
    instance, has held that the canon of constitutional avoidance can render an otherwise ambiguous
    statute unambiguous for Chevron purposes. See SWANCC, 
    531 U.S. at 172
    –74; Edward J.
    DeBartolo Corp. v. Fla. Gulf Coast Bldg. & Constr. Trades Council, 
    485 U.S. 568
    , 575–76
    (1988).
    After employing all of the traditional tools of construction in this case, I would find that
    the statutory “machinegun” definition unambiguously excludes bump stocks for the reasons I
    identified at the outset. The circuit courts that find this statutory definition ambiguous, by
    contrast, violate two of the Supreme Court’s interpretive principles at this stage of Chevron.
    First, these circuit courts give the type of “reflexive deference” to the ATF that the
    Supreme Court has rejected when deciding whether a statute is unambiguous under Chevron.
    Pereira, 138 S. Ct. at 2120 (Kennedy, J., concurring); cf. Kisor, 
    139 S. Ct. at 2415
    . These courts
    identify an ambiguity and defer to the ATF based on an “interpretive puzzle” that they identify
    but do not even attempt to solve. Epic, 138 S. Ct. at 1630. Consider, for example, the reasons
    why the D.C. Circuit found the phrase “single function of the trigger” ambiguous. Guedes,
    920 F.3d at 29–31. The court suggested that this phrase “admits of more than one interpretation”
    because it could refer to the mechanical actions of the trigger or the human actions of the
    shooter. Id. at 29. From there, however, the court made little effort to discern which of the two
    meanings best fits the context using any, much less all, of our traditional tools of interpretation.
    Id. at 29–31; see Pereira, 
    138 S. Ct. at 2116
    –18. The court thus did not ask whether one of the
    two possible perspectives better comports with the way in which the word “function” is normally
    used or with the statutory definition as a whole (both of which point to the trigger’s mechanical
    perspective as the proper reading). See Gun Owners, 992 F.3d at 471; cf. Kisor, 
    139 S. Ct. at 2415
    .
    A comparison of this “cursory analysis” to recent Supreme Court decisions shows the
    stark conflict in approaches. Pereira, 138 S. Ct. at 2120 (Kennedy, J., concurring); see, e.g., SAS
    Inst. Inc. v. Iancu, 
    138 S. Ct. 1348
    , 1354–58 (2018); Esquivel-Quintana, 
    137 S. Ct. at 1568
    –72.
    In Pereira, for example, the relevant statute’s meaning turned in part on the preposition “under.”
    See 138 S. Ct. at 2117. Like the D.C. Circuit, the Court readily admitted that this “chameleon”
    No. 19-1298                    Gun Owners of Am., Inc. v. Garland                        Page 46
    word could convey many distinct meanings, some of which favored the government and some of
    which favored the private party. Id. (citation omitted). Unlike the D.C. Circuit in Guedes,
    however, the Court did not call it a day at that point. Rather, it recognized that a careful textual
    parsing of the statute as a whole pointed to one unambiguous meaning. Id.; see id. at 2114–16.
    The circuit courts that found the Bump-Stock Rule ambiguous should have done the same.
    Second, these circuit courts wrongly throw out the rule of lenity when interpreting the
    statutory “machinegun” definition at Chevron step one. See Aposhian, 958 F.3d at 982–84;
    Guedes, 920 F.3d at 27–28. The Supreme Court has told us that we must use the standard
    canons of construction to decide whether a statute is unambiguous at this stage. See Epic, 
    138 S. Ct. at 1630
    ; SWANCC, 
    531 U.S. at 173
    –74. And the rule of lenity is one of the most
    traditional tools in our interpretive “toolkit.” Kisor, 139 S. Ct. at 2415; see Wiltberger, 18 U.S.
    at 95. Well before Chevron, for example, the Supreme Court refused to follow a regulatory
    interpretation of a law with civil and criminal applications because the agency’s reading would
    have done “violence to the well-established principle that penal statutes are to be construed
    strictly.” FCC v. Am. Broad. Co., 
    347 U.S. 284
    , 296 (1954). Within the Chevron framework,
    moreover, if a canon of construction such as the rule of lenity “resolves a statutory doubt in one
    direction, an agency may not reasonably resolve it in the opposite direction.” Carter, 736 F.3d at
    731 (Sutton, J., concurring). Ambiguity “in this situation is a congressional choice” in favor of a
    narrow interpretation of the criminal law, “not a delegation to the agency.” Arangure, 911 F.3d
    at 342. So even assuming that any ambiguity remained in the statutory “machinegun” definition,
    the rule of lenity would resolve that ambiguity against the Bump-Stock Rule’s broad reading.
    The courts that take the opposite view rely on a footnote from Babbitt that rejected the
    use of the rule of lenity when deferring to the Secretary’s regulation implementing the “take”
    prohibition in the Endangered Species Act. 
    515 U.S. at 704 n.18
    ; see Guedes, 920 F.3d at 27.
    Recall, however, that this Act includes an express delegation of criminal rulemaking authority to
    the Secretary to implement this prohibition. 16 U.S.C. § 1540(a)(1), (b)(1). Thus, Babbitt is best
    read as an express-delegation case, not as one that “rest[ed] on Chevron’s fiction” that Congress
    intends to give agencies interpretive authority over ambiguous texts. Cuozzo, 136 S. Ct. at 2148
    (Thomas, J., concurring). For that type of express delegation, perhaps the rule of lenity should
    No. 19-1298                      Gun Owners of Am., Inc. v. Garland                    Page 47
    kick in later to govern the interpretation of the agency’s implementing regulation (as Babbitt
    seemed to suggest). See 
    515 U.S. at 704 n.18
    ; see also M. Kraus & Bros., 
    327 U.S. at 622
    . But
    we need not decide how the rule of lenity interacts with such express delegations. This case
    involves Chevron’s fiction, not an express delegation. And the logic of the Supreme Court’s
    precedent leaves no doubt that traditional canons of construction like the rule of lenity apply at
    Chevron’s first step. SWANCC, 
    531 U.S. at 173
    –74; Arangure, 911 F.3d at 343–44.
    * * *
    By continuously firing at rapid speeds with one activation of the trigger, machine guns
    can inflict great harm in short periods. And no doubt many people believe that rifles equipped
    with bump stocks share the same dangerous traits that led Congress to ban machine guns.
    Bump-Stock Rule, 83 Fed. Reg. at 66,520. So even though these newer devices might not fall
    “within the letter” of the statutory “machinegun” ban, courts may be tempted to treat them as
    covered anyway because they fall within its underlying “spirit.” Holy Trinity Church v. United
    States, 
    143 U.S. 457
    , 459 (1892). In a country with a fluid separation of powers between the
    branches of government, this judicial approach of enlarging a statute through “equitable”
    interpretation rather than legislation might not be problematic. See John F. Manning, Textualism
    and the Equity of the Statute, 101 Colum. L. Rev. 1, 8 (2001). In our country, however, the
    judiciary has long had a narrower duty: “to apply, not amend, the work of the People’s
    representatives.” Henson v. Santander Consumer USA Inc., 
    137 S. Ct. 1718
    , 1726 (2017). This
    duty leaves the policy debate over whether to ban bump stocks where it belongs—with the
    legislative branch accountable to the people. And since that branch has not seen fit to ban bump
    stocks or give a federal agency the power to do so, I must respectfully dissent from our judgment
    affirming the district court’s decision in this case.
    ENTERED BY ORDER OF THE COURT
    ___________________________________
    Deborah S. Hunt, Clerk