Wayne Messam is best known, if you’ve heard of him at all, as the other mayor running for president — in his case, not quite as successfully as South Bend, Indiana’s mayor, Pete Buttigieg. The mayor of Miramar, Florida, has not found much of an audience or appeared in any debates. He has raised a mere $93,812 and a small campaign staff. And now, according to internal campaign documents and interviews with eight former Messam campaign staffers and contractors, his campaign appears to be in near-total disarray. The documents and staffers, some of whom spoke on the condition of anonymity...