The Tenth Amendment in Practice

The Tenth Amendment reserves to the states or the people the powers not delegated to the federal government. For much of the twentieth century it had little independent force. In United States v. Darby in 1941 the Supreme Court called it a truism, and in National League of Cities v. Usery in 1976 the Court held that Congress could not apply federal wage rules to state employees performing traditional government functions, only to overrule that decision in Garcia v. San Antonio Metropolitan Transit Authority in 1985, which said the states' protection lies mainly in the political process.

Since the 1990s the Court has developed the anti-commandeering doctrine. In New York v. United States in 1992 it held that Congress may not order state legislatures to enact laws, in Printz v. United States in 1997 that it may not order state officers to carry out federal programs, here background checks for gun purchases, and in Murphy v. NCAA in 2018 that it may not forbid states from repealing their own laws, striking down a federal ban on state-authorized sports betting. In Gregory v. Ashcroft in 1991 it also required Congress to speak clearly before intruding on core state functions.

The doctrine lets states and cities decline to help enforce federal law, the basis for sanctuary policies that limit cooperation with immigration detainers, which courts have generally upheld. Since 2025, litigation has centered on whether the federal government may withhold grants from sanctuary jurisdictions, raising both Tenth Amendment and spending power questions. The same principle has protected states that legalized marijuana or declined to enforce certain gun laws. Supporters say anti-commandeering preserves political accountability, while critics say it hampers national policy and is applied selectively.