Patrick Kennedy's exit opens a door for Buddy Cianci, who could join Jim Traficant in the felon caucus. * * * But if Kennedy is a rare breed of one kind -- the melancholy politician -- then his departure may clear the way for another type of odd duck entirely, and one that’s much more fun. Buddy Cianci, the former mayor of Providence -- former because of the small matter of a federal felony conviction -- is thinking about running for Kennedy's seat, presumably as an independent. * * * If he is a candidate, Cianci will join a rarefied...