The Commerce Clause allows Congress to regulate activity within a state if the activity has a substantial economic effect on interstate commerce.
Respondents were California residents who suffered from a variety of serious medical conditions and had sought to avail themselves of medical marijuana pursuant to the terms of the Compassionate Use Act. After an investigation, county officials concluded that one respondent's use of marijuana was entirely lawful under California law; nevertheless, federal agents seized and destroyed all six of her cannabis plants.Respondents brought an action against the Attorney General of the United States and the head of the DEA seeking injunctive and declaratory relief prohibiting the enforcement of the federal Controlled Substances Act (CSA).
May Congress, under its commerce power, forbid the cultivation and use of marijuana in compliance with California law?
The Court held that the regulation of marijuana under the CSA was squarely within Congress' commerce power because production of marijuana meant for home consumption had a substantial effect on supply and demand in the national market. Given the enforcement difficulties in distinguishing between marijuana cultivated locally and marijuana grown elsewhere, and concerns about diversion into illicit channels, the Court had no difficulty concluding that Congress had a rational basis for believing that failure to regulate the intrastate manufacture and possession of marijuana would leave a gaping hole in the CSA. Congress was acting well within its authority of the Commerce Clause, U.S. Const., art. I, § 8.