By Joe Johns

Harrisburg, PA (CNN) - A Pennsylvania judge upholds the state's controversial voter identification law, which requires voters to show a state issued photo ID.

The Pennsylvania court ruling is another skirmish in the country's emotional battle over voting rights this election year. More than a dozen states have passed new voting rights laws, including the one in the swing state of Pennsylvania, which is requiring people to show photo ID in order to vote.

Opponents went to court to try to block the law, saying it could disenfranchise up to 100,000 people, especially minorities and older or sick voters who are more likely not to have acceptable photo identification; people like 93-year-old Viviette Applewhite, one of the lead plaintiffs in the case.

"And I just think it's terrible because it's so many people that don't have ID, and they're not going to be able to vote," said Applewhite.

Republican commonwealth Judge Robert Simpson ruled that the opponents trying to keep the law from being enforced did not establish that disenfranchisement of voters was immediate or inevitable.

In Harrisburg, the legislator who wrote the law said disenfranchisement was never intended.

"The only ones it disenfranchises are those individuals who are trying to perpetrate election fraud," said Rep. Daryl Metcalfe.

But the commonwealth of Pennsylvania acknowledges that it would not be able to prove a lot of voter fraud in court, even if it tried.

Pennsylvania is also the state where a top GOP legislator recently seemed to suggest the voter law would help Republicans win back the White House this fall.

"Voter ID, which is going to allow Gov. Romney to win the state of Pennsylvania elected, done," said Rep. Mike Turzai.

Opponents say it just shows something other than fraud motivated the legislation.

"In the past decade, that they have found only about 10 instances of in-person voter fraud and those were mostly instances where people were simply confused and didn't know what the rules were in their area," said Nicole Austin-Hillery with the Brennan Center for Justice.

[Reporter]: "So this about voter suppression in your view?"

"In my view and in the view of the Brennan Center it's about keeping certain voters from the polls," said Austin-Hillery.

The Justice Department is now studying the Pennsylvania law, which representative Metcalfe, the author of the law, claims is a waste of time.

"I think it's a fishing expedition, where they're really over reaching," said Metcalfe. "They've demanded documents from us through our Department of Transportation and demanded information that many Pennsylvanians would object to."

CNN