Federalism

The Constitution creates two levels of government, each sovereign within its sphere and each acting directly on the people. The national government holds only the powers listed in the Constitution, while the states retain a general police power to legislate for health, safety, and welfare, a division confirmed by the Tenth Amendment. Under the Supremacy Clause, valid federal law prevails when the two conflict. Madison described the result in Federalist No. 39 as partly national and partly federal.

For its first century and a half, federalism was largely dual, often pictured as a layer cake, with separate federal and state responsibilities. The New Deal and the Great Society produced cooperative federalism, a marble cake in which programs are funded federally but run by states, as with Medicaid, highways, unemployment insurance, and food assistance. Federal grants to state and local governments now exceed a trillion dollars a year. There are also about 90,000 local governments, counties, cities, school districts, and special districts, all created under state law.

Federal courts set the outer limits. Congress may encourage states with grant conditions, but under New York v. United States in 1992, Printz v. United States in 1997, and Murphy v. NCAA in 2018, it may not commandeer state legislatures or officials to carry out federal programs. Federalism is invoked by whichever side is out of power nationally: states have resisted federal policy on immigration enforcement, marijuana, environmental rules, health care, and election administration under administrations of both parties.