An Arizona voter law requiring proof of citizenship has been struck down by the U.S. Supreme Court.
In a 7-2 vote, justices ruled Monday that Proposition 200, an Arizona voter-registration provision enacted in 2004, was pre-empted by federal law -- namely, the 1993 National Voter Registration Act.
The Arizona law required voters to prove their citizenship by providing documentation, The New York Times reports. But that went far beyond what the federal law requires, the Court explained.
Different Laws, Different Requirements
Federal law allows voters to swear by penalty of perjury that they are citizens of the United States by checking either a "yes" or "no" box on a federal form, accompanied by their signature.
Arizona's law, on the other hand, required documentation that would be very difficult for illegal immigrants to obtain, such as a driver's license, birth certificate, naturalization papers, or a passport, according to the Times.
In an opinion written by Associate Justice Antonin Scalia, the Court held that Arizona was not allowed to tack on additional requirements to the federal law -- especially not without federal approval -- and that Arizona's law did not operate in sync with the federal law.
Supremacy Clause in Action
Justice Scalia's opinion did seem to sympathize with the need for more stringent citizenship standards. However, this is a rather classic example of the Supremacy Clause striking out state law.
The Supremacy Clause, a clause within the United States Constitution, determines what happens when both state and federal laws address the same issue.
Generally speaking, the state law can remain in effect if it doesn't conflict with the federal law. If there are any inconsistencies, however, the federal law always trumps the state law, which is exactly what happened here.