For decades the Tenth Amendment was dismissed as a truism. Then it grew teeth.

The text says the powers not delegated to the United States by the Constitution, nor prohibited by it to the states, are reserved to the states respectively, or to the people. United States v. Darby (1941) called it a truism, stating nothing that had not already been settled by the structure of the document itself.

That reading did not hold.

This episode runs Authorize, Constrain, Gap on federalism’s reserved-powers clause. Authorize: whatever is left over belongs to the states or the people. Constrain: New York v. United States (1992) struck down a provision that forced states to take title to radioactive waste, holding that Congress may not compel a state legislature to enact a federal program. Printz v. United States (1997) extended that to state executive officers, invalidating a federal requirement that local sheriffs conduct background checks. Murphy v. NCAA (2018) applied the same principle to strike a federal ban on state authorization of sports wagering.

That line of cases is the anti-commandeering doctrine, and it has real modern consequences: it is a significant reason states can decline to assist in enforcing federal policy in areas from firearms to immigration to cannabis.

Then the Gap. Congress cannot command, but it can spend, and conditional federal funding does much of the same work by other means. Where persuasion becomes compulsion remains contested.

The anti-commandeering line is narrower than it is usually described. It restricts the federal government from directing state officials to administer federal programs. It does not, by itself, limit what Congress may regulate directly.

• United States v. Darby, 312 U.S. 100 (1941)
• New York v. United States, 505 U.S. 144 (1992)
• Printz v. United States, 521 U.S. 898 (1997)
• Murphy v. NCAA, 584 U.S. 453 (2018)

Citations verified against CourtListener.

Season 0 of DIFTCL: Doctrine Deep Dives runs one episode per amendment, twenty to thirty minutes each: what the text authorizes, how doctrine constrains it, and where the gap falls.

Browse the full season

Narration is AI-generated. Legal education, not legal advice. Consult a licensed attorney in your jurisdiction.