A judge's decision Wednesday to uphold the new Pennsylvania voter identification law shifted attention to the state's highest court, which could now determine if the requirement will be imposed on Election Day.

Attorneys for the plaintiffs had asked the judge to stop the law from taking effect as part of a constitutional challenge. Their complaint claims the law would make it disproportionately harder for seniors, minorities and others to vote in the Nov. 6 general election.

"Our concern is that you cannot wait until after Election Day to figure out that people lost their right to vote," says Judith Browne Dianis, co-director of the Advancement Project, which is the co-counsel for the plaintiffs. "We wanted to make sure the voters of Pennsylvania were protected going into this election, and that their right to vote wasn't encumbered by an unnecessary barrier."

Pennsylvania state court Judge Robert Simpson declined to rule on whether the law violates the state constitution. But in refusing to grant an injunction against the law, the judge said the plaintiffs failed to prove that voter disenfranchisement would be "immediate or inevitable."

Attorneys for the plaintiffs said they will immediately appeal to the state Supreme Court. The Associated Press reports:

"At the state Supreme Court, votes by four justices would be needed to overturn Simpson's ruling. The high court is currently split between three Republicans and three Democrats following the recent suspension of Justice Joan Orie Melvin, a Republican who is fighting criminal corruption charges."

Simpson, a Republican, said he was "convinced" the state "will fully educate the public" about the new requirement and enact the law "in a nonpartisan, even-handed manner."

The judge also pushed back against plaintiffs' claims that they can't obtain a state photo ID, one of the cards allowed under the law, because they lack the necessary documents such as a birth certificate. He cited in his ruling the state's plans to issue a special photo ID for those voters:

"Moreover, considering the believable testimony about the pending DOS photo IDs for voting, and the enhanced availability of birth confirmation through the Department of Health for those born in Pennsylvania, I am not convinced any qualified elector need be disenfranchised. ... Further ... based on the availability of absentee voting, provisional ballots, and opportunities for judicial relief for those with special hardships, I am not convinced any of the individual Petitioners or other witnesses will not have their votes counted in the general election."

Attorneys for the plaintiffs say that as many as 1 million voters lack the forms of photo identification accepted under the law. The judge rejected the figure as critics' "attempts to inflate the numbers." He said he believed state officials' estimate of between 1 percent and 9 percent of registered voters — or 82,723 to 744,507 people, based on state voter data.

Separately, the Justice Department is investigating whether minority voters are disproportionately represented among those who lack proper ID under the new law.

In November, voters in 30 states will have to present some form of identification at the polls. Ten of the states will require photo identification, including the presidential battlegrounds of Florida, Michigan, Virginia (pending federal approval) and now possibly Pennsylvania.

Legal battles over state voter ID laws and other election restrictions has sparked a national debate over voting rights and the potential impact these measures could have on voter turnout.

Proponents of the Republican-led initiatives say they will prevent voter fraud and shore up the election system. Nine of the 11 states that passed photo ID laws since 2010 have Republican governors.

A new study of more than 2,000 election-fraud cases since 2000 found that in-person voter impersonation, which ID laws are intended to prevent, "is virtually nonexistent."

Opponents, mainly Democrats and voting and civil rights groups, say the measures are intended to suppress turnout among minorities and young people, who tend to vote for Democratic candidates.

President Obama's re-election bid is pushing for strong turnouts of young and minority voters, whom plaintiffs in the cases say are among the likeliest to not have acceptable IDs. The Obama administration, through the Justice Department, has used the Voting Rights Act to block some of the initiatives, including voter ID laws in Texas and South Carolina.

With just 12 weeks before Election Day, photo ID laws in these other states remain in limbo:

Mississippi: A voter-approved constitutional amendment is under Department of Justice review. Mississippi is one of several states, including New Hampshire, South Carolina, Virginia and Texas, with a history of voter discrimination that must obtain federal approval to change election procedures.

New Hampshire: The measure is under Justice Department review after the state legislature overrode the governor's veto of the voter ID bill. Voters would be able to show a variety of identification forms, but several of the options will be eliminated in September 2013.

South Carolina: A trial before a three-judge panel of the U.S. District Court in Washington is scheduled to begin Aug. 27. The Justice Department twice blocked the law. If it is struck down, a separate law would require voters to show a non-photo ID on Election Day.

Texas: The U.S. District Court in Washington is expected to rule by Aug. 31. If Texas loses, an existing law will require a non-photo ID at the polls.

Virginia: A version more liberal than most others, by allowing a wide range of picture IDs, is under Justice Department review. In a move apparently to pre-empt legal claims of voter suppression, the governor has ordered the state to send new registration cards to every active voter.

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