While election results aren't usually affected, voter fraud is common. And electoral integrity is perhaps more important than the outcome. In the fall of 2008, Tarrell Campbell was a student at Southern Illinois University at Edwardsville. With his three separate masterÂ’s degrees, he had been on a college campus, somewhere, for more than a decade. He was so interested in the outcome of the 2008 presidential election that he cast a ballot in Illinois, then drove across a Mississippi River bridge to his hometown of St. Louis and voted again.Last week, Mr. Campbell entered a guilty plea to federal voter...