Legal Sidebari
Does the President Have the Power to Legalize
Marijuana?
Updated November 4, 2021
The legal status of marijuana has been a topic of recurring interest in recent years, as states, federal
legislators, and federal executive agencies consider how to regulate cannabis and its derivatives. What
role can the President play in determining the legal status of a controlled substance such as marijuana?
That question came to the forefront during the 2020 Democratic presidential primary, with multiple
candidates supporting legalization of marijuana and several pledging to legalize the substance nationwide
if elected, either indirectly through administrative proceedings or directly by executive order. More
recently, some commentators have called on President Biden to end criminal penalties for marijuana
possession and use or grant clemency to federal marijuana offenders. Although the President cannot
directly remove marijuana from control under federal controlled substances law, he might order executive
agencies to consider either altering the scheduling of marijuana or changing their enforcement approach.
This Sidebar outlines the laws that apply to controlled substances like marijuana, then analyzes several
approaches a president might take to change controlled substances law as written or as enforced. The
Sidebar closes with a discussion of key considerations for Congress related to presidential power over
controlled substances regulation.
Controlled Substances Law
Federal Law: the Controlled Substances Act
Under federal law, unless a statutory exemption applies, most cannabis and cannabis derivatives are
classified as marijuana, a Schedule I controlled substance under the Controlled Substances Act (CSA).
(The CSA generally uses an alternative spelling, “marihuana,” but this Sidebar uses the more common
spelling.) The CSA imposes a comprehensive regulatory framework on certain drugs and other
substances—whether medical or recreational, legally or illicitly distributed—that pose a significant risk of
abuse and dependence. The framework broadly aims to protect public health from those risks while
ensuring that patients have access to pharmaceutical controlled substances for medical purposes. To
advance those related goals, the CSA (1) requires entities engaged in legitimate activities involving
controlled substances to register with the government and take steps to prevent diversion and misuse and
(2) imposes criminal penalties for unauthorized activities involving controlled substances.
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Substances become subject to the CSA through placement in one of five lists, known as Schedules I
through V. A lower schedule number carries greater restrictions, so controlled substances in Schedule I are
subject to the most stringent controls. Schedule I controlled substances have no currently accepted
medical use, and it is illegal to produce, dispense, and possess such substances except in the context of
federally approved scientific studies. By contrast, substances in Schedules II through V have accepted
medical uses and may be dispensed by prescription for medical purposes.
As discussed further below, a substance can be placed in a CSA schedule, moved to a different schedule,
or removed from control under the CSA either by legislation or through an administrative rulemaking
process overseen by the Drug Enforcement Administration (DEA) and based on criteria set out in the
CSA. The CSA also directs the Attorney General (who has delegated CSA scheduling authority to DEA)
to schedule substances as required to comply with the United States’ treaty obligations. Congress placed
marijuana in Schedule I in 1970 when it enacted the CSA. Since that time, DEA has denied multiple
petitions from stakeholders seeking to move marijuana to a less restrictive schedule or remove the
substance from control under the CSA. In 2018, Congress amended the CSA to provide that hemp—
defined to include cannabis products containing no more than 0.3 percent of the psychoactive cannabinoid
delta-9 tetrahydrocannabinol (THC)—is not a controlled substance subject to the CSA. (Hemp products
may, however, be subject to regulation under other provisions of federal law.)
State Laws
In addition to the federal CSA, each state has its own controlled substances laws. As a general matter,
state controlled substances laws often mirror federal law and are relatively uniform across jurisdictions
because almost all states have adopted a version of the Uniform Controlled Substances Act. However,
there is not a complete overlap between drugs subject to federal and state control.
Marijuana regulation is one area where the gap between federal and state controlled substance laws is
particularly salient. In sharp contrast to the stringent federal control of marijuana, in recent decades nearly
all the states have changed their laws to permit the use of marijuana (or other cannabis products) for
medical purposes. In addition, 18 states and the District of Columbia have passed laws removing certain
state criminal prohibitions on recreational marijuana use by adults.
Notably, however, states cannot actually legalize marijuana, because the states cannot change federal law
and the Constitution’s Supremacy Clause dictates that federal law takes precedence over conflicting state
laws. As long as marijuana is a Schedule I controlled substance under the CSA, all unauthorized activities
involving marijuana are federal crimes anywhere in the United States, including in states that have
purported to legalize medical or recreational marijuana.
Presidential Power to Legalize or Decriminalize Marijuana
Discussion of whether the President can legalize or decriminalize marijuana raises the question of what it
means to “legalize” or “decriminalize” a Schedule I controlled substance. “Legalization” of marijuana
could mean moving the substance from Schedule I to another schedule of the CSA so that it would be
legal to produce, distribute, and possess marijuana for medical purposes, subject to the CSA’s registration
requirements; or it could mean removing marijuana from control under the CSA altogether.
“Decriminalization” generally refers to maintaining some form of prohibition of marijuana but enforcing
the ban only through non-criminal sanctions, such as civil monetary penalties.
Descheduling or Rescheduling Under the CSA
Either Congress or the executive branch has the authority to change the status of marijuana under the
CSA. Congress can change the status of a controlled substance through legislation: Congress included
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marijuana in Schedule I by legislation when it enacted the CSA, and has more recently passed legislation
to impose controls on other substances, including synthetic cannabinoids and fentanyl analogues. In the
alternative, the CSA empowers DEA to make scheduling decisions through the notice-and-comment
rulemaking process, in consultation with the Department of Health and Human Services (HHS) (HHS has
delegated its factfinding role in this process to the Food and Drug Administration (FDA)). The CSA
provision directing DEA to schedule controlled substances as “required by United States obligations
under international treaties” may limit the agency’s authority to relax controls of marijuana; another CRS
report discusses considerations for Congress related to marijuana’s status under international drug control
treaties.
If the President sought to act in the area of controlled substances regulation, he would likely do so by
executive order. However, the Supreme Court has held that the President has the power to issue an
executive order only if authorized by “an act of Congress or . . . the Constitution itself.” The CSA does
not provide a direct role for the President in the classification of controlled substances, nor does Article II
of the Constitution grant the President power in this area (federal controlled substances law is an exercise
of Congress’s power to regulate interstate commerce). Thus, it does not appear that the President could
directly deschedule or reschedule marijuana by executive order.
Although the President may not unilaterally deschedule or reschedule a controlled substance, he does
possess a large degree of indirect influence over scheduling decisions. The President could pursue the
appointment of agency officials who favor descheduling, or use executive orders to direct DEA, HHS,
and FDA to consider administrative descheduling of marijuana. The notice-and-comment rulemaking
process would take time, and would be subject to judicial review if challenged, but could be done
consistently with the CSA’s procedural requirements. In the alternative, the President could work with
Congress to pursue descheduling through an amendment to the CSA.
Presidential Pardons and Prosecutorial Discretion
Just as the CSA does not grant the President the authority to unilaterally change the classification of a
controlled substance, it also creates no presidential power to alter the general penalties applicable to
controlled substances offenses. While the President cannot change the law as written, he has substantial
control over how the law is enforced. For instance, the Constitution grants the President the power “to
grant Reprieves and Pardons for Offences against the United States.” That clemency power extends to all
federal offenses, “except in Cases of Impeachment.” The President may grant a pardon at any time after
an offense is committed: before the pardon recipient is charged with a crime, after a charge but prior to
conviction, or following conviction. The power is not limited to pardons for individual offenders: the
President may also issue a general amnesty to a class of people. It therefore appears that the President
could provide clemency for some or all past federal marijuana-related offenses without making any
changes to the CSA. However, such an exercise of the clemency power might not address all possible
collateral legal consequences of marijuana-related activities, because some of those consequences do not
depend on a person being charged with or convicted of a CSA violation. Clemency also would not prevent
prosecution of future offenses if the same President or a future administration ended the policy of
amnesty. Furthermore, the presidential clemency power extends only to federal offenses; it does not affect
offenses under state law.
In addition to, or instead of, granting clemency, the President could direct the Department of Justice
(DOJ) to exercise its discretion not to prosecute some or all marijuana-related offenses. Although DOJ
generally enjoys significant independence, particularly with respect to its handling of specific cases, the
President has the authority to direct DOJ as part of his constitutional duty to “take Care that the Laws be
faithfully executed.” DOJ is primarily responsible for prosecuting criminal violations of the CSA and
possesses significant prosecutorial discretion in doing so. Under the Obama administration, DOJ issued
several guidance memoranda outlining enforcement priorities related to marijuana. Although that
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guidance expressly reserved DOJ’s full authority to enforce the CSA, it suggested that prosecutors should
not prioritize enforcement against low-risk activities, including individual use of medical marijuana.
Under the Trump Administration, DOJ rescinded the Obama-era guidance in 2018, but retains broad
discretion to decide what federal offenses to prosecute. Like the pardon power, DOJ prosecutorial
discretion would limit prosecution only for federal offenses, and would provide no guarantee against
future changes to DOJ’s enforcement policy.
State Law
If the President worked with DEA or Congress to remove marijuana from Schedule I of the CSA, it might
raise the question of how the change in federal law would interact with state laws that criminalize some or
all marijuana-related activities. Under the United States’ federalist system of government, the President
has no direct power to change state law or compel the states to adopt federal policies. Pursuant to the
Supremacy Clause, Congress can preempt state law through federal statutes like the CSA. However, the
CSA provides that it does not preempt state laws “unless there is a positive conflict between [the CSA]
and that State law so that the two cannot consistently stand together.” If marijuana were rescheduled or
descheduled at the federal level, it would be possible for people to comply with both the CSA and more
stringent state laws—for example, by abstaining from using marijuana. Thus, that change to federal law
standing alone would not alter the status of marijuana under state law.
Considerations for Congress
If Congress wishes to remove or scale back federal legal restrictions on marijuana beyond what the
executive branch chooses to pursue, it has significant authority to do so. While the CSA does not grant the
President the power to change the status of a controlled substance or the punishments for controlled
substance offenses, Congress unquestionably holds the power to amend the CSA to reschedule or
deschedule a controlled substance or change applicable penalties. If the legislature decides to relax federal
regulation of marijuana, bills currently pending before Congress would move marijuana to a less
restrictive schedule or remove the substance from control entirely. (Amending the CSA would not change
the status of cannabis under other federal laws, including the Federal Food Drug & Cosmetic Act.) In the
alternative, Congress could choose to limit the enforcement of federal marijuana law without altering the
substance’s classification under the CSA. For example, an appropriations rider enacted every year since
FY2014 prohibits DOJ from using taxpayer funds to prevent the states from “implementing their own
laws that authorize the use, distribution, possession, or cultivation of medical marijuana.”
In addition, while Congress cannot directly change state laws, it may be able to override state laws via
preemption or enact measures designed to encourage the states to change their own laws. With respect to
the first option, when legislating pursuant to an enumerated power, Congress can expressly preempt state
laws and could likely amend the CSA to override state marijuana controls. As an analogous precedent, the
2018 farm bill carved out non-psychoactive hemp from the CSA’s regulation of marijuana and prohibited
the states from banning the interstate transport of hemp. As for the second option, Congress can use its
spending power to encourage the states to adopt certain policies by conditioning federal funds on the
enactment of desired legislation.
If, in the alternative, Congress seeks to maintain existing controls, it would have some authority to do so
even if the executive branch decided to reduce legal restrictions on marijuana or limit enforcement of
marijuana laws. The CSA is a statutory regime, and Congress has the ultimate authority over what
substances are subject to federal control. Thus, if DEA chose to move marijuana to a less restrictive CSA
schedule or remove it from control entirely, Congress could potentially overturn DEA’s determination or
enact legislation directly placing marijuana in Congress’s preferred schedule. However, if the executive
branch elected to issue pardons or grant amnesty for marijuana offenses, or to exercise
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prosecutorial discretion to decline to prosecute such offenses, Congress’s options would be more limited.
Congress could restrict funding to DOJ if it disagreed with the agency’s enforcement strategy, but the
legislature cannot directly force DOJ to pursue certain cases. As for the pardon power, the main checks on
executive clemency are political, and there is no way for Congress to rescind a pardon once it has issued.
Author Information
Joanna R. Lampe
Legislative Attorney
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff
to congressional committees and Members of Congress. It operates solely at the behest of and under the direction of
Congress. Information in a CRS Report should not be relied upon for purposes other than public understanding of
information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role.
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