Voters in Louisiana’s 6th District have two choices to represent them in Washington, D.C.: a political newcomer, who served in Gov. Bobby Jindal’s cabinet, or a well-known former governor, who also happens to be a convicted felon. By nearly all measures, Republican Garret Graves, who served as Jindal’s coastal secretary for six years, has the upper hand heading into a Dec. 6 runoff against former Gov. Edwin Edwards, a Democrat. Edwards, a colorful character from a different political era, once famously quipped to reporters that the only way he’d lose an election bid was “if I’m caught in bed with...