I dunno.. Maybe Collins, Thune, Jindal, Daniels, or Ryan. It really all depends on who the candidate is. I have no faith that Pawlenty brings anything to the table that will bring people out to vote. Anyone who thinks that he could actually help the state swing to Republicans, or make it a swing at this point are crazy.
Collins will never be accepted due to pro-choice stance.
Remember how Buchanan threaten to run 3rd party candidacy if Dole selects pro-choice running-mate. That attitude never changed.
People are concerned about the economy, deficit, taxation, and terrorism. Collins also is slightly more conservative than Snowe, so there is more acceptance for her if she moves slightly to right if she were on a national ticket.