Americans live under two governments at once, national and state, and the Constitution divides power between them on purpose.
The Founders called this a “compound republic.” James Madison wrote in Federalist No. 45 that the powers delegated to the federal government are “few and defined,” while those remaining with the states are “numerous and indefinite.”
The Building Blocks
- Enumerated powers: Article I, Section 8 lists what Congress may do, such as taxing, borrowing, regulating interstate and foreign commerce, coining money and raising armed forces
- Necessary and Proper Clause: lets Congress pass laws needed to carry out those powers
- Supremacy Clause (Article VI): valid federal laws override conflicting state laws
- Tenth Amendment: “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”
Where the Lines Are Drawn
Much of the debate turns on the Commerce Clause. Since the New Deal, the Supreme Court has read it broadly, but it has also set limits. In United States v. Lopez (1995), the Court struck down a federal law banning guns near schools because carrying a gun is not economic activity that substantially affects interstate commerce.
The Court has also said the federal government cannot commandeer the states. In Printz v. United States (1997), it held Congress cannot order state officers to carry out federal programs, and in Murphy v. NCAA (2018), it held Congress cannot dictate what laws state legislatures may or may not pass.
Washington does have another tool: money. Congress can attach conditions to federal grants, as long as the conditions are clear, related to the program and not coercive. In NFIB v. Sebelius (2012), the Court found that threatening all of a state’s existing Medicaid funding crossed that line.
Federalism Today
These principles are being tested again. Some of the most active debates of 2026, including whether federal policy can displace state artificial intelligence laws, and how far state and local police cooperate with federal agencies, are federalism questions at their core.
Federalism is not a partisan principle. Both parties invoke states’ rights when they disagree with Washington and federal power when they control it. The Constitution’s structure is meant to apply no matter who is in charge.
Keep Digging With Truth Agent
This article is a starting point. Truth Agent puts the public record at your fingertips, including the Constitution, federal law, regulations, court opinions and oversight reports, so you can compare federal and state law side by side and follow the court cases that draw the line without relying on anyone’s summary, including ours.
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