WASHINGTON — The Supreme Court ruled Monday that states can require voters to produce photo identification without violating their constitutional rights, validating Republican-inspired voter ID laws such as Georgia's.

In a splintered 6-3 ruling, the court upheld Indiana's strict photo ID requirement, which Democrats and civil rights groups said would deter poor, older and minority voters from casting ballots. Its backers said it was needed to prevent fraud.

It was the most important voting rights case since the Bush v. Gore dispute that sealed the 2000 election for George W. Bush. But the voter ID ruling lacked the conservative-liberal split that marked the 2000 case.

The law "is amply justified by the valid interest in protecting 'the integrity and reliability of the electoral process,'" Justice John Paul Stevens said in an opinion that was joined by Chief Justice John Roberts and Anthony Kennedy. Stevens was a dissenter in Bush v. Gore in 2000.

Justices Samuel Alito, Antonin Scalia and Clarence Thomas also agreed with the outcome, but wrote separately.

Justices Stephen Breyer, Ruth Bader Ginsburg and David Souter dissented, just as they did in 2000.

Georgia Secretary of State Karen Handel praised the ruling.

"It's welcome news," said Handel, who attended the Supreme Court arguments in January. "This is a good step forward for the integrity of our elections and the accuracy of the vote."

Georgia required voter IDs during elections last September and the February primaries. Just about the only complaints the Secretary of State's office received were that voters were receiving too many notices reminding them they needed voter IDs at the polls, Handel said.

All voters found not to have driver's licenses were sent three mailings alerting them of the need for the official identification, Handel said. "It's been a very structured and detailed outreach effort we put together and has been very successful," she said.

In September, a federal judge in Rome praised the secretary of state's education efforts when upholding a challenge to Georgia's voter ID law.

U.S. District Court Judge Harold Murphy found the law did not impose a significant burden on the right to vote. He also found evidence showing state officials had made "exceptional efforts to contact voters and explain the requirements of the law."

The lawsuit was filed in 2005 by a number of organizations, including Common Cause/Georgia, the League of Women Voters of Georgia, the NAACP and the Georgia Legislative Black Caucus.

The organizations filed a notice to appeal Murphy's ruling to the 11th U.S. Circuit Court of Appeals in Atlanta. But both the organizations and the state agreed to delay litigating the appeal until the U.S. Supreme Court decided the Indiana case.

David Brackett, an Atlanta lawyer representing the plaintiffs, said the high court's ruling allows the appeal to go forward.

Brackett said Monday's ruling gives some help to the organizations that challenged Georgia's law. In one part of his ruling, Murphy found that the plaintiffs did not have standing to bring the lawsuit because none of them could prove specific harm. But the U.S. Supreme Court agreed Monday that the Democratic Party of Indiana had standing, Brackett said, predicting this should allow the Georgia case to clear that hurdle.

Brackett also said the litigation in the Georgia case was more developed than in Indiana's. "We think we have a stronger case and are not precluded by this ruling," he said.

More than 20 states require some form of identification at the polls. Monday's decision also could spur efforts to pass similar laws in other states.

Ken Falk, legal director of the American Civil Liberties Union of Indiana, said he hadn't reviewed the decision, but he was "extremely disappointed" by it. Falk has said voter ID laws inhibit voting, and a person's right to vote "is the most important right." The ACLU brought the case on behalf of Indiana voters.

The case concerned a state law, passed in 2005, that was backed by Republicans as a way to deter voter fraud. Democrats and civil rights groups opposed the law as unconstitutional and called it a thinly veiled effort to discourage elderly, poor and minority voters -- those most likely to lack proper ID and who tend to vote for Democrats.

There is little history in Indiana of either in-person voter fraud -- of the sort the law was designed to thwart -- or voters being inconvenienced by the law's requirements. For the overwhelming majority of voters, an Indiana driver license serves as the identification.

"We cannot conclude that the statute imposes 'excessively burdensome requirements' on any class of voters," Stevens said.

Stevens' opinion suggests that the outcome could be different in a state where voters could provide evidence that their rights had been impaired.

But in dissent, Souter said Indiana's voter ID law "threatens to impose nontrivial burdens on the voting rights of tens of thousands of the state's citizens."

Scalia, favoring a broader ruling in defense of voter ID laws, said, "The universally applicable requirements of Indiana's voter-identification law are eminently reasonable. The burden of acquiring, possessing and showing a free photo identification is simply not severe, because it does not 'even represent a significant increase over the usual burdens of voting.'"

Stevens said the partisan divide in Indiana, as well as elsewhere, was noteworthy. But he said that preventing fraud and inspiring voter confidence were legitimate goals of the law, regardless of who backed or opposed it.

Indiana provides IDs free of charge to the poor and allows voters who lack photo ID to cast a provisional ballot and then show up within 10 days at their county courthouse to produce identification or otherwise attest to their identity.

Stevens said these provisions also help reduce the burden on people who lack driver licenses.

Staff writer Bill Rankin contributed to this article.