Justice Marshall,
with whom Justice Blackmun joins, concurring.
I join the Court’s opinion but write separately to emphasize two points underlying my vote. The first is my conclusion that the opportunity of a defendant to challenge the substance of a temporary scheduling order in the course of a criminal prosecution is essential to the result in this case. Section 811(h)(6) of Title 21 U. S. C. expressly prohibits di*170rect review of a temporary scheduling order in the Court of Appeals but says nothing about judicial review of such an order in other settings. Under established rules of construction, we must presume from Congress’ silence on the matter that it did not intend to foreclose review in the enforcement context. See Estep v. United States, 327 U. S. 114, 120-122 (1946). See generally McNary v. Haitian Refugee Center, Inc., 498 U. S. 479, 496 (1991); Abbott Laboratories v. Gardner, 387 U. S. 136, 140-141 (1967). An additional consideration reinforces this principle here. As the Court notes, judicial review perfects a delegated-lawmaking scheme by assuring that the exercise of such power remains within statutory bounds. See, e. g., Skinner v. Mid-America Pipeline Co., 490 U. S. 212, 218-219 (1989). Because of the severe impact of criminal laws on individual liberty, I believe that an opportunity to challenge a delegated lawmaker’s compliance with congressional directives is a constitutional necessity when administrative standards are enforced by criminal law. Cf. United States v. Mendoza-Lopez, 481 U. S. 828, 837-839 (1987); Hart, The Power of Congress to Limit the Jurisdiction of Federal Courts: An Exercise in Dialectic, 66 Harv. L. Rev. 1362, 1379-1383 (1953). We must therefore read the Controlled Substances Act as preserving judicial review of a temporary scheduling order in the course of a criminal prosecution in order to save the Act’s delegation of lawmaking power from unconstitutionality. Cf. Webster v. Doe, 486 U. S. 592, 603-604 (1988).
The second point that I wish to emphasize is my understanding of the breadth of the Court’s constitutional holding. I agree that the separation of powers doctrine relates only to the allocation of power betiveen the Branches, not the allocation of power within a single Branch. But this conclusion by no means suggests that the Constitution as a whole is indifferent to how permissibly delegated powers are distributed within the Executive Branch. In particular, the Due Process Clause limits the extent to which prosecutorial and *171other functions may be combined in a single actor. See, e. g., Morrissey v. Brewer, 408 U. S. 471, 485-487 (1972). Petitioners raise no due process challenge in this case, and I do not understand anything in today’s decision as detracting from the teachings of our due process jurisprudence generally.