Tricky
Briefly immortal
I certainly hope Stephen Colbert isn't in consideration. He'd be a horrible senator. I love his show and he's doing far more good keeping tabs on politicians than he'd do on the inside if he were a politician himself.
No chance, in fact, he said so himself in his "out of character" interview, noting "Anyone who has said the things I've said with a straight face, directly to a camera, could never run for office."*
*or words to that effect.