In any case, Thompson is hardly a 'citizen politician.' He is very much a part of the DC power structure.
As for his winning attributes, listen to Lamar Alexander: EARTH TO LAMAR: FRED THOMPSON LOOKING THE PART AIN'T ENOUGH (41-second video FLUB)
What if Thompson's sole purpose is to give McCain the nomination by skimming off just enough conservatives from Rudy? (NB: gross is net, i.e., McCain has no conservative support to lose.) FRED'S GREATEST ROLE?: an alternative theory of Senator Thompson's not-yet candidacy