The use, sale, and possession of cannabis over 0.3% THC in the United States, despite state laws, is illegal under federal law. As a Schedule I drug under the federal Controlled Substances Act of 1970, cannabis over 0.3% THC (legal term marijuana) is considered to have "no accepted medical use" and have a high potential for abuse and physical or psychological dependence. Cannabis use is illegal for any reason, with the exception of FDA-approved research programs. However, individual states have enacted legislation permitting exemptions for various uses, mainly for medical and industrial use but also including recreational use.
Cannabis for industrial uses (hemp) was made illegal to grow without a permit under the Controlled Substances Act because of its relation to cannabis as a drug, and any imported products must adhere to a zero tolerance policy. The Agricultural Act of 2014 allows for universities and state-level departments of agriculture to cultivate cannabis for research into its industrial potential.
As a psychoactive drug, cannabis continues to find extensive favor among recreational and medical users in the United States. As of 2019, eleven states, two U.S. territories, and the District of Columbia have legalized recreational use of cannabis. Thirty-three states, four U.S. territories, and D.C. have legalized medical use of the drug. Multiple efforts to reschedule cannabis under the Controlled Substances Act have failed, and the United States Supreme Court has ruled in United States v. Oakland Cannabis Buyers' Cooperative (2001) and Gonzales v. Raich (2005) that the federal government has a right to regulate and criminalize cannabis, whether medical or recreational. As a result, cannabis dispensaries are licensed by each state; these businesses sell cannabis products that have not been approved by the U.S. Food and Drug Administration, nor are they legally registered with the federal government to sell controlled substances. Although cannabis has not been approved, the FDA recognizes the potential benefits and has approved two drugs that contain components of marijuana.
The ability of states to implement cannabis legalization policies was weakened after US Attorney General Jeff Sessions rescinded the Cole Memorandum on January 4, 2018 and issued a new memo instructing US Attorneys to enforce federal law related to marijuana. The Cole memo, issued by former Deputy Attorney General James Cole in 2013, urged federal prosecutors to refrain from targeting state-legal marijuana operations. Regarding the medical use of cannabis, the Rohrabacher–Farr amendment still remains in effect to protect state-legal medical cannabis activities from enforcement of federal law.
Roger Roffman, a professor of social work at the University of Washington, asserted in July 2013 that "approximately 3.6 million Americans are daily or near daily users." Peter Reuter, a professor at the School of Public Policy and the Department of Criminology at the University of Maryland, College Park, said that "experimenting with marijuana has long been a normal part of growing up in the U.S.; about half of the population born since 1960 has tried the drug by age 21." A World Health Organization survey found that the United States is the world’s leading per capita marijuana consumer. The 2007 National Survey on Drug Use & Health prepared by the U.S. Department of Health and Human Services indicated that 14.4 million U.S. citizens over the age of 12 had used marijuana within a month. The 2008 survey found that 35 million Americans were willing to tell government representatives that they had used marijuana in the past year.
According to the 2001 National Survey on Drug Use and Health by the Substance Abuse and Mental Health Services Administration, a branch of the U.S. Department of Health and Human Services, 41.9% (more than 2 in 5) of all Americans 12 or older have used cannabis at some point in their lives, while 11.5% (about 1 in 9) reported using it "this year."
Medical use is a common reason why people use marijuana. According to the National Institute on Drug Abuse, "The term medical marijuana refers to using the whole unprocessed marijuana plant or its basic extracts to treat a disease or symptom." However, the U.S Food and Drug Administration (FDA) has not officially approved marijuana as a medicine.
Until the passage of the 2018 United States farm bill, under federal law, it was illegal to possess, use, buy, sell, or cultivate cannabis in all United States jurisdictions, since the Controlled Substances Act of 1970 classified marijuana as a Schedule I drug, claiming it has a high potential for abuse and has no acceptable medical use. Despite this federal prohibition, some state and local governments established laws attempting to decriminalize cannabis, which has reduced the number of "simple possession" offenders sent to jail, since federal law enforcement rarely targets individuals directly for such relatively minor offenses. Other state and local governments ask law enforcement agencies to limit enforcement of drug laws with respect to cannabis. However, under the Supremacy Clause of the United States Constitution, federal law preempts conflicting state and local laws. In most cases, the absence of a state law does not present a preemption conflict with a federal law.
The federal government criminalized marijuana under the Interstate Commerce Clause, and the application of these laws to intrastate commerce were addressed squarely by the United States Supreme Court in Gonzales v. Raich, 352 F. 3d 1222 in 2005.
In January 2009, President Barack Obama's transition team organized a poll to clarify some of the top issues the American public wants to have his administration look into, and two of the top ten ideas were to legalize the use of cannabis. In July 2009, Gil Kerlikowske, Director of the Office of National Drug Control Policy, clarified the federal government's position when he stated that "marijuana is dangerous and has no medicinal benefit" and that "legalization is not in the president's vocabulary, and it's not in mine." However, a January 2010 settlement between the U.S. Drug Enforcement Administration and the Wo/Men's Alliance for Medical Marijuana (WAMM) provided an example confirming the administration policy as communicated by Attorney General Eric Holder, as WAMM reached an agreement that allowed them to re-open after being shut down by the federal government in 2002.
Following the 2012 presidential election, the Office of National Drug Control Policy under the Obama administration stated that it "steadfastly opposes legalization of marijuana and other drugs because legalization would increase the availability and use of illicit drugs, and pose significant health and safety risks". In February 2014, the administration issued guidelines to banks for conducting transactions with legal marijuana sellers so these new businesses can stash away savings, make payroll, and pay taxes like any other enterprise. However, marijuana businesses still lack access to banks and credit unions due to Federal Reserve regulations.
On August 29, 2013, the Justice Department adopted a new policy (known as the Cole memo) regarding the enforcement of federal law in states that have legalized non-medical cannabis. The policy specified that commercial distribution of cannabis would be generally tolerated, except in certain circumstances, such as if violence or firearms are involved, the proceeds go to gangs and cartels, or if the cannabis is distributed to states where it is illegal.
On December 11, 2014, the Department of Justice told U.S. attorneys to allow Native American tribes on reservations to grow and sell marijuana, even in states where it is illegal. The policy will be implemented on a case-by-case basis and tribes must still follow federal guidelines.
On May 30, 2014, the United States House of Representatives passed the Rohrabacher–Farr amendment, prohibiting the Justice Department from spending funds to interfere with the implementation of state medical marijuana laws. The amendment became law in December 2014, and must be renewed each year in order to remain in effect.
On March 10, 2015, U.S. Senators Rand Paul, Kirsten Gillibrand, and Cory Booker introduced the Compassionate Access, Research Expansion and Respect States Act or CARERS Act. The bipartisan bill would move cannabis from Schedule I to Schedule II of the Controlled Substances Act. This would allow states with medical cannabis laws to legally prescribe it, and allow for much easier research into its medical efficacy. The bill would also allow grow sites besides the University of Mississippi, which has long been the sole supplier of cannabis for academic research, to supply cannabis for study.
The Food and Drug Administration has approved two synthetic cannabis drugs for treating cancer and other medical issues. The federal government of the United States continues to argue that smoked cannabis has no recognized medical purpose (pointing to a definition of "medical purpose" published by the DEA, not the Food and Drug Administration, the National Institutes of Health, the Centers for Disease Control, or the office of the U.S. Surgeon General and the U.S. Public Health Service). Many officials point to the difficulty of regulating dosage of cannabis (a problem for treatment as well as research), despite the availability (in Canada and the United Kingdom) of dosage-controlled Sativex. The United States has also pressured other governments (especially Canada and Mexico, with which it shares borders) to retain restrictions on marijuana.
On December 20, 2018, President Donald Trump signed the farm bill which descheduled hemp, making cannabis under 0.3% THC legal once again.
In February 2019, three researchers used MedMen as a case study to illustrate their concerns with marijuana companies' marketing practices. The authors criticized MedMen's use of health claims without health warnings and their appeals to youth. They called for federal regulators to investigate the marketing practices of MedMen and other US-based marijuana companies.
In 1973, Oregon became the first state to decriminalize cannabis, and in 2012 Colorado and Washington became the first states to legalize recreational use. As of June 2019, eleven states (Alaska, California, Colorado, Illinois, Maine, Massachusetts, Michigan, Nevada, Oregon, Vermont, and Washington), the District of Columbia, the Northern Mariana Islands, and Guam have legalized recreational use of cannabis, with all but Vermont and D.C. permitting its commercial sale. Another 15 states (plus the U.S. Virgin Islands) are considered to have decriminalized cannabis.
In 1996, California became the first state to legalize the medical use of cannabis when voters approved Proposition 215. As of January 2019, thirty-three states, four out of five permanently inhabited U.S. territories, and the District of Columbia have legalized medical cannabis. Fourteen other states have more restrictive laws limiting THC content, for the purpose of allowing access to products that are rich in cannabidiol (CBD), a non-psychoactive component of cannabis.
The National Center for Natural Products Research in Oxford, Mississippi is the only facility in the United States that is federally licensed by the Drug Enforcement Administration to cultivate cannabis for scientific research. The facility is part of the School of Pharmacy at the University of Mississippi, and cultivates cannabis through a contract with the National Institute on Drug Abuse, to which it provides the cannabis.
The federal government has so far refused to grant any other licenses for the cultivation of cannabis, which has had a hindering effect on the amount of research conducted. The cannabis supplied by NIDA has been criticized by researchers for a variety of reasons, including high amounts of stems and seeds, high mold and yeast levels, low THC content, and low diversity of strains available. NIDA has also been criticized for the length of time in which it responds to proposals, and for favoring research on the harms caused by cannabis over research on the health benefits of cannabis. In August 2016, the DEA announced intention to grant additional cultivation licenses, but as of July 2017, 25 applications had been submitted to the DEA and none had been approved, with no timeline given by the DEA for the approval of any licenses.
Research conducted on cannabis also requires licensing from the DEA (specific to Schedule I drugs), and approval from the FDA as well. Prior to 2015, research also required approval from the U.S. Public Health Service, but this requirement was eliminated to make it less difficult for cannabis research to be approved. Numerous medical organizations in the U.S. have called for restrictions on cannabis research to be further eased, including the American Academy of Family Physicians, American Psychological Association, American Cancer Society, American Academy of Pediatrics, and the American Nurses Association.
The great majority of cannabis arrests are for possession. However, in 1997, the vast majority of inmates in state prisons for marijuana-related convictions were convicted of offenses other than simple possession.
According to the Federal Bureau of Investigation's annual Uniform Crime Report, there have been over twelve million cannabis arrests in the United States since 1996, including 749,825 persons for marijuana violations in 2012. Of those charged with marijuana violations in 2012, 658,231 (88%) were charged with possession only. The remaining 91,593 individuals were charged with "sale/manufacture", a category that does not differentiate for cultivation offenses, even those where the marijuana was being grown for personal or medical use. Marijuana arrests comprise almost one-half (48.3 percent) of all drug arrests reported in the United States. According to the American Civil Liberties Union, there were 8.2 million marijuana arrests from 2001 to 2010, and 88% of those arrests were just for having marijuana with them.
The Libertarian Party and the Green Party are known for advocating for the legalization of marijuana. There are also active cannabis political parties in at least five states. These include the Grassroots-Legalize Cannabis Party, the Legal Marijuana Now Party, the Legalize Marijuana Party, and the United States Marijuana Party.
In July 2016, delegates at the 2016 Democratic National Convention voted to approve a party platform calling for cannabis to be removed from the list of Schedule I substances, as well as calling for a "reasoned pathway for future legalization".
Gallup began polling the public as to the issue of legalizing cannabis in 1969; in that year 12% were in favor. The 2017 Gallup poll showed a record high of 64% in favor of legalizing cannabis, including a majority of Republicans for the first time.
According to a 2013 survey by Pew Research Center, a majority of Americans favored complete or partial legalization of cannabis. The survey showed 52% of respondents support cannabis legalization and 45% do not. College graduates' support increased from 39% to 52% in just three years, the support of self-identified conservative Republicans (a group not traditionally supportive of cannabis legalization) had increased to nearly 30%, and bipartisan support had increased across the board. The 2018 version of the poll showed public support had increased to 61%.
Attitudes regarding marijuana regulation changed as some states (Colorado, Washington, Oregon, Maine, and Alaska) passed their own laws legalizing marijuana for recreational use. According to a Gallup Poll published in December 2012, 64% of Americans believe the federal government should not intervene in these states.
A 2018 study in Social Science Research found that the main determinants of these changes in attitudes toward marijuana regulation since the 1990s were a decline in perception of the riskiness of marijuana, changes in media framing of marijuana, a decline in overall punitiveness, and a decrease in religious affiliation.
Marijuana legalization polled as very popular in 2019 according to three major national polls. In fact, research indicates that communities with legal, recreational marijuana use have seen home values rise more quickly than communities where recreational use remains illegal.