Consider the following blurb from the latest National Review:

During the last election, Cincinnati resident Melowese Richardson mailed in an absentee ballot, then voted in person, later explaining that she was afraid the absentee vote “wouldn’t count.” Richardson is a poll worker, so this is like a diner with an “Out to Lunch” sign on the door. Investigators have charged her and at least 18 other Hamilton County residents with illegal voting; some report say she may have cast as many as six votes. In response, Richardson (who still has an Obama/Biden sign on her lawn) has vowed to “fight it for Mr. Obama and for Mr. Obama’s right to sit as president of the United States.” Perhaps in Miss Richardson’s multiple votes we have finally found the explanation for those long lines at the polls.

While it’s not clear that a voter ID law would have stopped a Melowese Richardson, such a law could thwart other people with a similar disregard for voting rules. As John Hood has pointed out, a photo ID requirement also could make a difference on rare occasions in tightly contested races.