Michael Perez / AP

Gloria Gilman holds a sign during the NAACP voter ID rally to demonstrate the opposition of Pennsylvania's new voter identification law, Thursday, Sept. 13, 2012, in Philadelphia.

The fight over Pennsylania's controversial voter ID legislation is far from over, but opponents of the law see a light at the end of the tunnel after Tuesday's state Supreme Court ruling.

"We are optimistic this restrictive voter ID law will not be in effect for the 2012 election," said the Brennan Center's Democracy Program Director Wendy Weiser in a statement.

In a 4-2 ruling [PDF], the Pennsylvania Supreme Court ordered the lower Commonwealth Court to revisit the law, saying that the lower court would have to block the law unless it was convinced that legally eligible Pennsylvania residents would have "liberal access" to newly issued identification, and that no disenfranchisement would occur. The Supreme Court also ordered the Commonwealth Court to come to a final decision before October 2.

So, does that mean the law is likely to be blocked before election day?

"Its entirely an empirical question," as to whether voters are being disenfranchised, said Dan Tokaji, a senior fellow in election law at Ohio State University's Moritz College of Law. "And if the state can't satisfactorily answer the empirical question, then the injunction will have to be issued."

Though Tokaji was careful to say he didn't want to prejudge the court's decision, his "atmospheric sense" was that "it's going to be really hard for a signficant number of people to get the voter ID, and so the injunction will have to be issued."

"I think that the legal conclusion that the Pennsylvania Supreme Court reaches is one that’s very favorable to voters," Advancement Project Co-Director Penda D. Hair told Talking Points Memo. "They seem to say there needs to be actual evidence that voters are not being disenfranchised or else an injunction needs to be entered."

Larry Norden, the deputy director of the Brennan Center's Democracy Program, agreed. "Certainly it's not impossible the court will find that [no disenfranchisement would occur under the law], but it's going to be much more difficult than with the earlier standard they applied," he said. The Commonwealth Court had previously upheld the law using a less stringent standard for what qualifies as disenfranchisement.

Explaining the difference between the two standards, Norden said the lower court had upheld the law by arguing that "in general, people should be able to get these IDs." The Supreme Court, he said, found "that the real standard the court should have been deploying was for the state to show there would be no disenfranchisement in the November election as a result of the voter ID law." In other words, for the law to be upheld, the Commonwealth Court would have to find that every eligible voter without an ID could be reasonably expected to obtain an ID in the relatively short period of time between now and Election Day.

Norden said he was "fairly confident" that the evidence suggested otherwise, pointing to a recent story on the website of the Philadelphia Inquirer about the difficulties one woman had in obtaining her ID.

"There already seems to be a decent amount of evidence, under the standard that the Supreme Court is saying the lower court needs to apply, that it's going to be impossible for at least some people to get the ID in time for the November election," Norden said.