1. In United States v. Lopez (1995), a federal law mandating a “gun free zone" on and around public school campuses was struck down because, the Supreme Court ruled, there was no clause in the Constitution authorizing it. 10 th Amendment

2. In 1997, the Court again ruled that the Brady Handgun Violence Protection act violated the Tenth Amendment, The act required state and local law enforcement officials to conduct background checks on persons attempting to purchase handguns 10 th Amendment

3. Ratified in 1971, provides that powers not granted to the national government nor prohibited to the states by the Constitution of the United States are reserved to the states or the people. 10 th amendment