Federal marijuana laws are the supreme law of the land.

Do the feds have to obey state laws legalizing the possession of small amounts of marijuana, such as those laws in Colorado and the state of Washington? The answer is no; the federal government can enforce its laws outlawing possession of marijuana at any time, but they have chosen not to do so in those states permitting the possession of small amounts of marijuana, as long as the “states and local governments that have enacted laws authorizing marijuana-related conduct . . . implement strong and effective regulatory and enforcement systems that . . . address the threat those state laws could pose to public safety, public health, and other law enforcement interests.” See the August 29, 2013 memorandum sent to all US Attorneys by the Department of Justice, and an accompanying press release from the  DOJ. 

Federal laws are the supreme law of the land “and the Judges in every State shall be bound thereby, any Thing in the Constitution or Laws of any State to the Contrary notwithstanding.” US Const. Art. VI, Cl 2. Further, the Constitution grants Congress the power to “regulate Commerce with foreign Nations, and among the several States, and with the Indian Tribes.” US Const. Art.I, § 8, Cl 3. The US Supreme Court, in Gonzales v. Raich, 545 U.S. 1 (U.S. 2005), was faced whether a seizure of six medicinal marijuana plants in California by local and federal agents was lawful. In Raich, the defendants’ growth and possession of six marijuana plants was legal under California’s medical marijuana law and illegal under the federal Controlled Substances Act (CSA). The defendants claimed in a lawsuit against the US Attorney General and the head of the DEA that the seizure was unlawful under Commerce Clause, the DueProcess Clause of the Fifth Amendment, the Ninth and Tenth Amendments of the Constitution, and the doctrine of medical necessity. The US Supreme Court upheld the seizure, holding that “the CSA is a valid exercise of federal power,” Id., at 9 (U.S. 2005), “the regulation is squarely within Congress' commerce power because production of the commodity meant for home consumption . . . has a substantial effect on supply and demand in the national market for that commodity,” Id., at 19, and that this power “includes the power to prohibit commerce in a particular commodity.” Id., n. 29.