The state law had been challenged by the Mexican American Legal Defense and Education Fund and Indian tribes. The opponents of the state law held that its requirements deterred legal voters who did not have the necessary paperwork.
However, the Supreme Court also observed that Arizona had the right to assert its argument to ask for proof of citizenship in a separate litigation. As far as voting in federal elections were concerned that was in the arena of the federal law from 1993 and a state law could not prevail in imposing separate provisions in the same matter.
Under the federal law, in order to vote in federal elections one needs to provide one among several accepted proofs of identification and sign a statement declaring citizenship. No proof of citizenship is required.
Though the 7-2 majority held that state law was pre-empted by the federal statute which stated that states must “accept and use” a federal registration form, Justice Clarence Thomas and Justice Samuel Alito dissented in separate opinions and observed that states alone should decide voter qualifications.
The majority held that it was still open to Arizona to challenge the current form in a separate litigation and Justice Scalia observed, “That alternative means of enforcing its constitutional power to determine voting qualifications remains open to Arizona here.”
Arizona’s voter registration law has been hotly debated in the state and in other arenas. While Republicans stood by it, claiming that the law was designed to reduce voter fraud, Democrats maintained it was aimed at preventing minorities from voting, as minorities historically voted for Democrats.
Monday’s ruling would also affect three other states which have similar laws – Alabama, Georgia, and Kansas.