I still think that McCain had to choose a woman as his running mate, who could have picked up all those votes of the bitterly disappointed Clinton supporters, preferably a minority candidate.
With that said, his best choices would have been Condoleezza Rice or, even better, Ileana Ros-Lehtinen from the most important swing state.
I'm not sure about Ileana Ros-Lehtinen, if only because she had never won a statewide election, and I just personally would hesitate with picking Congressmen.
I actually heard that Kay Bailey Hutchison was someone they considered. I think she would have held her own as a pick, but I'm not sure how the base would have liked her and how her ties towards the oil industry in Texas would have played in a national election (remember how they went on and on and on about how Palin "stood up to big oil").
I think they considered Jindal, Pawlenty, Thune, Crist (FL), and Tom Ridge.
