Block v. Hirsh

Congressional police power refers to the federal government's constitutionally defined jurisdiction in maintaining domestic order. Under the Constitution the federal government is limited in their ability to police the states. The power to regulate interstate commerce is the only provision that permits the federal government to intervene in matters of domestic order outside of federally defined crimes such as treason, kidnapping, and crimes involving drugs. Under the Tenth Amendment, the states are reserved the right to construct and enforce criminal law. However, the federal government has stretched the power to regulate interstate commerce to expand their police power.

The alleged mishandling of the Waco and Ruby Ridge incidents federal law enforcement agents, which were highly publicized, have stimulated debate over the jurisdiction of congressional police power. In United States v. Lopez (1995) the Supreme Court ruled that the federal government does not have a police power to define or enforce a state criminal code.