What is federalism?

Federalism is the constitutional system that divides governing power between a national government and the fifty state governments, with each level holding authority directly over its citizens. It is one of the structural choices the Founders made in 1787 to control concentrated power. Article I, Section 8 lists the enumerated powers of Congress, including taxing, borrowing, regulating interstate commerce, declaring war, raising armies, coining money, establishing post offices, and making all laws necessary and proper to carry out those powers. Article VI's Supremacy Clause makes valid federal law and treaties superior to state law. The Tenth Amendment, ratified in 1791, balances those grants by reserving to the states or the people any powers not delegated to the federal government and not prohibited to the states.

States therefore handle most criminal law, family law, property law, contract law, public schools, professional licensing, traffic rules, and local elections. Some powers are concurrent, exercised by both levels. Both the federal and state governments tax, borrow, build courts, run prisons, and exercise eminent domain. Some powers are exclusive to the federal government, including the power to make treaties, regulate immigration, and coin money. Some are denied to both, like passing ex post facto laws.

Federalism has shifted considerably over time. The early republic operated under a model often called dual federalism, where federal and state powers were treated as largely separate spheres. The New Deal, World War II, and the civil rights era expanded federal authority through the Commerce Clause and the Fourteenth Amendment, producing what scholars call cooperative federalism, in which Washington funds programs the states administer. Recent decades have seen the Supreme Court draw clearer limits in cases like United States v. Lopez in 1995 and NFIB v. Sebelius in 2012, which struck down parts of federal laws as exceeding enumerated powers or coercing the states.

The system creates fifty laboratories where different policies on health care, education, criminal justice, and elections can be tested, while the federal government secures national defense, a single market, and uniform constitutional rights.