By Greg Stohr, Bloomberg News (TNS)

WASHINGTON — The U.S. Supreme Court cleared the way for Wisconsin to implement a voter-identification law that opponents say is one of the strictest in the nation.

Rejecting an appeal by civil rights groups, the justices Monday gave a victory to Republicans, including Wisconsin Governor Scott Walker, who have championed voter-ID laws around the country. Wisconsin is one of 30 states with ID laws and one of 17 that enacted measures since the Supreme Court upheld an Indiana statute in 2008.

Civil rights groups say ID requirements disproportionately affect minority and low-income voters while doing little if anything to protect against fraud. The organizations pressing the Wisconsin appeal said 300,000 registered voters in that state lack a qualifying ID.

“The right to vote is the foundational element of American democracy,” the groups argued. “Increasingly restrictive voter ID laws like Wisconsin’s Act 23 unjustifiably burden the voting rights of millions of registered voters, particularly African Americans and Latinos.”

Wisconsin officials led by Walker, a potential presidential candidate, defended the law. They argued that it will impose a minimal burden on voters while providing more assurance of a fraud-free election.

“In Wisconsin, as elsewhere, the overwhelming majority of voters already have qualifying ID,” Wisconsin Attorney General Brad Schimel argued. “For those who lack ID, obtaining one and bringing it to the polling place is generally no more of a burden than the process of voting itself.”

In October the Supreme Court blocked the Wisconsin law from applying to the Nov. 4 election. A lower court had revived the law weeks earlier, and civil rights groups told the high court at the time that hasty implementation would mean widespread confusion.

Lower courts have largely backed voter-ID laws. In a notable exception, a federal trial judge said Texas’s statute was the product of intentional discrimination. That case is now before a federal appeals court and could make its way to the Supreme Court before the 2016 election.

Unlike with Wisconsin, the Supreme Court let the Texas law take effect for the 2014 election.

In the latest Wisconsin appeal, groups led by the League of United Latin American Citizens argued that the 2011 state law violated the U.S. constitutional guarantee of equal protection and the 1965 Voting Rights Act.

Wisconsin’s law lets voters use any of eight forms of identification, including in-state driver’s licenses, state-issued photo IDs for non-drivers and military IDs. The state also accepts some student identification cards, though not those from the University of Wisconsin campuses.

A federal trial judge invalidated the measure, saying it would deter many residents from voting. The judge also said the state hadn’t pointed to any recent instances of voter impersonation in Wisconsin.

A three-judge federal appeals panel in Chicago reversed that decision, pointing to new rules the state issued to help people obtain the documentation they need to get IDs. Officials took that step after the Wisconsin Supreme Court, in a separate case, said people must be able to get IDs without having to pay a fee for documents.

The panel’s ruling drew a rebuke from Judge Richard Posner, who argued unsuccessfully for reconsideration by a larger group of judges. Posner said voter-impersonation fraud was “a mere fig leaf for efforts to disenfranchise voters.”

The Supreme Court in 2008 upheld Indiana’s voter-ID law on a 6-3 vote. Writing the court’s lead opinion, Justice John Paul Stevens said voter fraud was a real risk that “could affect the outcome of a close election.”

Stevens said the record in the Indiana case “does not provide any concrete evidence of the burden imposed on voters who currently lack photo identification.”

The Wisconsin civil rights groups say the trial in their case produced that type of evidence. State officials say the two laws are indistinguishable after the changes required by the Wisconsin Supreme Court.

Photo: A Mary Burke supporter holds a sign promising to vote during a September, 2014  rally (Milwaukee Teachers’ Education Association/Flickr)