Following his defeat to Democrat John Bel Edwards in Saturday's Louisiana gubernatorial election, GOP Sen. David Vitter announced that he will retire from the Senate next year, ensuring another busy year of campaigning in a state with no shortage of ambitious politicians. Vitter's exit will set up an open-seat race in 2016, and the Republican side of the field is chock-full of potential candidates: GOP Reps. Charles Boustany and John Fleming, state Treasurer John Kennedy, retired Air Force Col. Rob Maness and Public Service Commissioner Scott Angelle could all make bids. The Democratic picture is less clear: New Orleans Mayor...