WHAT? How could you forget Mike Huckabee??
Anyway, if Obama is unpopular and turns out to be another Carter, then the Republicans will naturally go the way of Reagan and nominate Huckabee (who like Reagan was second in the primaries during a Democrat year).
If Obama is popular, then they will nominate Giuliani or Palin as a "throwaway card" so as to not damage candidates like Huckabee who actually have a chance in 2016.
Anyway, I predict the former situation. So, Huckabee is the nominee, wins the election and becomes the new Reagan.
Problem Huck was not second. He came in third in overal popular votes. Check the primaries page on this site. He was also third in the delegates till Romney got out and his delegates started to drift over to McCain as Romney had wished. Huck is no Reagan. Huck is a reincarnation of Huey Long. If he or anyone like him is nominated I can guarrantee less then 100 Electoral votes.
Caucusus Primaries Total
Romney 135,490 38.0% 4,525,036 21.73% 4,538,526
Huckabee 85,545 24.0% 4,179,514 20.07% 4,265,059
Romney beat Mike Huckabee to come in second in the popular vote by 273,467 votes. Of the 85,000 Huck got in Caucusus nearly half 40,000 came from his Iowa win and was based almost solely on Evengelicals. Huck came in 6th among non Evangelicals in IA. Huckabee would need a very divided field to win and I doubt he will get that like he had in 2008.
Prediction:Mike Huckabee will never be President of the US and will never be nominated by the GOP.