It’s set: The Pennsylvania Supreme Court last week announced that it will decide whether the state’s controversial voter ID law is constitutional. And in Philadelphia! Come on down: Sept. 13, City Hall.

A Republican Commonwealth Court judge upheld the law, which requires voters to present one of a set of valid forms of ID to vote and could disenfranchise thousands, earlier this month. The Supreme Court is split 3-3 because Justice Joan Orie Melvin was suspended after being charged with corruption, and a 3-3 split automatically upholds the lower court’s ruling.

One legal expert is not optimistic the Supremes will overturn the law, but court watchers are waiting to see whether Republican Chief Justice and former Philly DA Ron Castille might switch sides to join Democrats, as he has before.