Pawlenty, Romney, Giuliani, Huckabee, and Crist to start. Maybe Jindal. Maybe Brownback, though I think he's looking to 2016 he could change his mind. No doubt others will come crawling out of the woodwork, especially if Obama still looks as vulnerable as he's looking now.
Which Crist? The senator or the governor? Jindal I agree, but I believe he’s ineligible, but man enough to admit it...Pawlenty, possibly. He is talking a good game. The Simulus money could be a problem, and he’s already got hit by the RINO tag (like Gualini, Romny and Huckabee). Romny/Palin would make a better team than McCain/Palin did. As for Huckabee I personally disagree; he has some creepy ideas about nanny statism and is too liberal in some ways, but that’s just MPO.
Possibly DeMint. Pence. Hell, even Lou Dobbs is talking about it.