GWU law professor Spencer Overton, speaking on Common Cause’s election day media briefing, predicted provisional ballots cast by voters whose registration is challenged will be the likeliest cause of serious election snafus. The law doesn’t lay out specific ground for these challenges, nor clear guidelines for evidence or investigation–how is a judge to verify whether someone actually lives at a given address? Finally, the deadlines for counting as well as verifying these provisional ballots vary widely. In Florida, there is no deadline, but they’ll start counting them tonight; in Ohio, they have two weeks! “There’s so much play in the joints…it’s very probable that partisans can manipulate things,” Overton said, directing us to Ohio State University law school’s excellent election law site, which carries news updates, judges’ decisions and legal analysis.