Legal Question in Constitutional Law in Arizona

Re: What happens if a state law violates the Constitution?

A state law can be challenged in federal court, and if the court rules that it is unconstitutional on its face it becomes unenforceable. States usually appeal such rulings and, depending on the specifics of a given case, the statute may or may not remain in effect while the appeal is pending. The District Court's decision can be reversed by the Court of Appeal or by the Supreme Court, but if it isn't reversed then the state statute is void. State legislatures are not obligated to repeal the statute when this happens, but if it remains on the books it cannot be enforced.

Sometimes a statute only violates the constitution in some situations but not others. In those cases, the federal courts can limit the application of the statute without striking it entirely.