The Evolution of Marijuana as a Controlled Substance and the Federal-State Policy Gap

Marijuana is a psychoactive drug that generally consists of leaves and flowers of the cannabis sativa plant. Its history dates back thousands of years, but in the United States it became popular as a recreational drug in the early 20th century. Not long after its rise in popularity, the federal government began to exercise control over marijuana and other substances through its taxing authority, and it enacted criminal penalties for violations of drug laws. In 1970, the federal government enacted the Controlled Substances Act (CSA), which imposed a unified legal framework at the federal level to regulate certain drugs—whether medical or recreational, and legally or illicitly distributed. The CSA criminalized the manufacture, distribution, dispensation, and possession of marijuana, which included all of varieties of cannabis at the time (in 2018, the farm bill [P.L. 115-334] amended the CSA to exclude hemp—plant material that contains no more than 0.3% delta-9-tetrahydrocannabinol [delta-9-THC] on a dry weight basis). Under the CSA, marijuana and its derivatives are classified as Schedule I controlled substances, which means the cultivation (or manufacture), possession, and distribution of marijuana are illegal except for the purposes of sanctioned research. While the CSA definition of marijuana changed in 2018, which resulted in the removal of hemp from the definition of marijuana, the status of marijuana as a Schedule I substance has remained unchanged for over 50 years. Many states, however, have established a range of laws and policies allowing for the medical and recreational use of marijuana over the last several decades. Most of these states have deviated from an across-the-board prohibition of marijuana, and it is now more the rule than the exception that states have laws and policies allowing for some cultivation, sale, distribution, and possession of marijuana or low-THC cannabis—many of which are contrary to the CSA. As of April 1, 2022, 37 states, as well as Puerto Rico, Guam, the U.S. Virgin Islands, and the District of Columbia, allow for the comprehensive medical use of marijuana, while 11 additional states allow for the medical use of low-THC cannabis. Also, 18 states, the District of Columbia, Guam, and the Northern Mariana Islands allow for recreational use of marijuana. These developments have spurred a number of questions regarding potential implications of the federal and state marijuana policy gap for federal law enforcement activities, for individuals who comply with state marijuana law but violate federal marijuana law, and for the nation’s drug policies as a whole. Under the principles of federalism, the federal government may preempt state marijuana laws and enforce the CSA. Thus far, the federal response to state actions to legalize marijuana has largely been to allow states to implement their own laws on the drug. The gap between federal marijuana law and federal enforcement policy and the issues it creates continue each year, although Congress has partly addressed this gap by restricting the Department of Justice’s (DOJ’s) ability to expend funds to enforce the CSA in states that allow medical marijuana. DOJ has nonetheless reaffirmed that marijuana growth, trafficking, and possession remain crimes under federal law irrespective of states’ marijuana laws. To date, federal law enforcement has generally focused its efforts on criminal networks involved in the illicit marijuana trade. Many observers voice apprehension over possible negative outcomes of marijuana legalization, including, but not limited to, (1) potential increases in marijuana use, particularly among youth; (2) potential increases in traffic accidents involving marijuana-impaired drivers; (3) marijuana trafficking from states that have legalized it into neighboring states that have not; and (4) U.S. compliance with international treaties. Proponents of legalization have pointed to possible positive outcomes that could result from marijuana legalization, including a new source of tax revenue for states and a decrease in marijuana-related arrests that would free up resources for other law enforcement needs. Many states have yet to completely assess the full range of outcomes of their medical or recreational marijuana programs, particularly those that have only recently legalized the drug. The marijuana policy gap creates unique consequences for individuals who act in compliance with state law but violate federal law. As organizations and individuals have pressed forward with the manufacturing, sale, and use of marijuana, consequences of the gap have arisen—two of the more publicized consequences for individuals are termination of employment due to marijuana use in states that have legalized medical or recreational marijuana, and a range of implications for researchers and postsecondary students on college campuses. Other consequences include, but are not limited to, an inability to obtain or dismissal from certain types of employment, the inability to purchase and possess a firearm, inadmissibility for federal housing, and ineligibility for certain visas. The marijuana policy gap between the federal government and states has widened almost every year for over 25 years as more states legalize medical and/or recreational marijuana. It has only been a few years since states began to legalize recreational marijuana, but over 25 years since they began to legalize medical marijuana—no state has reversed its legalization, medical or recreational, since California first legalized medical marijuana in 1996. In addressing state-level legalization efforts and considering marijuana’s current placement on Schedule I of the CSA, Congress could take one of several routes. It could elect to take no action, thereby maintaining the federal government’s current marijuana policy and allowing the policy gap to expand if additional states legalize medical or recreational marijuana. Alternatively, it may decide that the CSA must be strictly enforced and not allow states to implement marijuana laws that conflict with the CSA. Or, it may take smaller steps to address the policy gap, such as continuing to include appropriations provisions that restrict DOJ’s ability to expend funds to enforce federal law. Congress could also choose to reevaluate marijuana’s classification as a Schedule I controlled substance. If Congress were to alter the federal status of marijuana by lowering its schedule or even creating a new schedule, it may devote more resources to the Food and Drug Administration (FDA) to manage and assess the many medical marijuana products available across the country. If Congress alters marijuana’s schedule, there are a number of issues that policymakers might address. These include, but are not limited to, issues surrounding availability of financial services for marijuana businesses, federal tax treatment, and the role of federal law enforcement in marijuana investigations. If Congress chooses to remove marijuana as a controlled substance under the CSA and remove criminal provisions, this would at least partly eliminate the policy gap with states that have authorized medical and recreational marijuana programs. Whether Congress decides to address the gap with the states or not, federal control of cannabis has evolved from the strict laws and enforcement policies of the 20th century to allowing most states to implement laws authorizing the production and distribution of marijuana. Among other things, Congress may halt and reverse this evolution, continue to relinquish federal criminal control, or alter or eliminate federal criminal control of cannabis entirely.