Supreme Court ruling could block other states from imposing new restrictions on citizens seeking to register to vote.

WASHINGTON -- The Supreme Court ruled handily Monday that Arizona cannot add to federal voter registration requirements by demanding proof of citizenship.
The ruling, which could impact other states as well, is at least a temporary victory for liberals who want to expand access to the polls and a defeat for conservatives concerned about potential election fraud.
In a 7-2 decision written by Justice Antonin Scalia, the court said Arizona's proof of citizenship requirement -- passed by voters in 2004 -- went too far beyond the 1993 federal "motor voter" law that was designed to simplify voter registration procedures.
The federal law requires registrants to claim U.S. citizenship on a mail-in post card, under penalty of perjury. The Arizona law requires separate physical proof of citizenship. The justices' decision upholds congressional authority over federal elections and could make it harder for states to impose additional restrictions.
However, Scalia said Arizona could try a different approach to challenge the federal law's pre-emption, thereby holding out the possibility that the state could resurrect its proof-of-citizenship requirement.
The federal law "forbids states to demand that an applicant submit additional information beyond that required by the federal form," Scalia said in announcing his decision from the bench. While he appeared to sympathize with the state's goal of requiring better proof of citizenship, he said it lacked the authority to do so without seeking federal approval.
His customary soul-mate on the right, Justice Clarence Thomas, argued in dissent that the Constitution gives states the authority to determine voters' qualifications, and the federal "motor voter" law cannot countermand it.
"I would construe the (federal) law as only requiring Arizona to accept and use the form as part of its voter registration process, leaving the state free to request whatever additional information it determines is necessary," Thomas said.
Four other states -- Alabama, Georgia, Kansas and Tennessee -- require proof of citizenship before residents can register to vote. About 30 states have voter identification requirements at the polls, designed to thwart impostors seeking to cast illegal ballots.
The ruling was hailed by voting-rights groups. "Today's decision sends a strong message that states cannot block their citizens from registering to vote by superimposing burdensome paperwork requirements on top of federal law," said Nina Perales, vice president of litigation for the Mexican American Legal Defense and Educational Fund.
The case represents the lesser of two voting rights cases before the court this term. Far more significant is Shelby County v. Holder, an Alabama county's challenge to the landmark Voting Rights Act of 1965, which requires mostly Southern states with a history of discrimination to clear proposed voting changes with the federal government before implementing them. Arizona is one of the states covered by the provision.
"It is our hope that the court will continue in this vein when it issues the Shelby v. Holder decision," said Barbara Arnwine, president of the Lawyers Committee for Civil Rights Under Law. "It would be a false promise for today's decision to promise equal access to the ballot and for an adverse ruling in Shelby to snatch this away."
While a decision in the Voting Rights Act case is anticipated this week or next, the Arizona case proved an easier nut for the justices to crack.
Arizona voters approved Proposition 200 in 2004, requiring more specific proof of citizenship. During the next three years, more than 30,000 people were turned away for failing to provide documentation. Voter registration dropped by 44% in Maricopa County, which includes Phoenix.
A federal district court upheld the referendum, but it was thrown out on appeal. The state then brought the case to the Supreme Court.
At the crux of the issue is the Constitution's elections clause, which says states can set the times, places and manner of holding federal elections -- but that Congress can make changes.
During oral arguments in March, conservative justices expressed sympathy for Arizona, which must fight a disproportionate share of the nation's battle against illegal immigration. Still, several of them joined in ruling that the state should have sought changes in the federal law rather than going around it. Only Thomas and Justice Samuel Alito dissented from the opinion.
The verdict came a year after the court issued a split decision on Arizona's first-in-the-nation immigration law. The court tossed out several provisions designed to crack down on illegal immigrants but upheld the most controversial one -- allowing police to check immigration papers while enforcing other laws.
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