But the case will not be heard or decided before next month's presidential election.
Arizona voters enacted Proposition 200 in 2004, which among other things required voters to provide "satisfactory evidence of U.S. citizenship in order to register to vote."
A federal judge refused to issue an injunction against the implementation of the law in a case brought by a coalition of Hispanic, Indian and civil rights groups. However, a federal appeals court panel, and then the entire U.S. Court of Appeals reversed, saying the law violated Article I of the U.S. Constitution and the National Voter Registration Act, which requires states to make it easier to register for federal elections.
Article I says in part the "Times, Places and Manner of holding Elections for Senators and Representatives,shall be prescribed in each State by the Legislature thereof; but the Congress may at any time by Law make or alter such Regulations, except as to the Places of chusing (choosing) Senators."
Arizona successfully asked the U.S. Supreme Court for review.
Among the identification evidence accepted under Proposition 200 are a driver's license, birth certificate, naturalization documents, and a U.S. Bureau of Affairs or tribal card number.
The law says each county recorder shall reject an application for registration not accompanied by such evidence.
The Inter Tribal Council of Arizona told the high court in its own brief on behalf of itself and other coalition members that the appeals court ruled correctly.