Kathie Purdy doesn’t mind the phone calls. And there have been a lot of them—producing a sustained buzzing from her iPhone throughout the nearly two weeks since Graham Platner announced that he would drop out of the Maine Senate race. At one point, Purdy’s device grew so hot that she had to take it out of its case to let it breathe. But that was okay, she told me. As chair of the York County Democratic Committee, it was her job to help guide Mainers through this confusing moment.What Purdy did not appreciate was the insinuation—from other Democrats, from members...