Mitt/JEB!
I have to ask, who do you think they would replace him with that could win?
You could make a decent case for almost any of the candidates that were running in the primaries, with some exceptions.
Some exceptions being:
Bush, a bit of an "oh no, not 3 times!" problem, being a Bush family member.
Graham, why bother, just go ahead and elect a Democrat.
Carson, not sure the Clintons wouldn't eat him alive, but he may have had a decent shot.
That guy, whose name escapes me (Gilmore?), that got something 14 votes?
Pataki may have been a tough sell.
The rest had a real shot at taking down Clinton, IMO.