The U.S. Supreme Court on Saturday denied a request to block a Texas law requiring voters in the state to show certain forms of identification before they cast a ballot.
The move comes after a U.S. appeals court on Tuesday granted a request by the state to stay a lower court decision that struck down the law, meaning the measure will be in effect for the November elections.
The decision, published early on Saturday morning, was unsigned and did not provide a supporting legal argument. Justice Ginsburg, joined by Justices Sotomayor and Kagan from the court's liberal wing, penned a six-page dissent.
"The greatest threat to public confidence in elections in this case is the prospect of enforcing a purposefully discriminatory law, one that likely imposes an unconstitutional poll tax and risks denying the right to vote to hundreds of thousands of eligible voters," Ginsburg wrote.
Last Thursday, U.S. District Judge Nelva Gonzales Ramos overturned the law, arguing it discriminated against Hispanics and African-Americans and impinged on their right to vote. Ramos said the law would effectively disenfranchise some 600,000 voters, a figure the state disputes.
On Tuesday, the New Orleans-based 5th U.S. Circuit Court of Appeals granted a request filed by the state asking for that ruling to be put on hold pending appeal.
The trial stemmed from a battle over stringent voter ID measures signed into law by Texas Republican Governor Rick Perry in 2011. The law, which supporters say will prevent voter fraud, requires voters to present photo identification such as a driver's license, passport or military ID card.
It is one of a series enacted in mostly Republican-governed states requiring voters to show certain forms of identification before being allowed to vote.
Saturday's ruling is a blow to the strategy of President Barack Obama's administration of challenging such laws, which it says discriminate by race.
The administration wants to counter a U.S. Supreme Court ruling in June 2013 that overturned parts of the Voting Rights Act. That ruling freed several states, mostly in the South, from strict federal oversight.
Opponents of the ID laws argue they are designed to reduce the turnout of certain groups of voters who are less likely to have such identification.
(Reporting by Curtis Skinner in San Francisco; Editing by Mark Potter, Larry King)