Re comment by charliehall, final sentence: I think you are underestimating the power of the moderate/business-friendly/country-club/establishment wing of the Republican party.
Jeb Bush would be a strong candidate in the general election, and the Republican party establishment would rather win than be ideologically pure (which, incidentally, is not a bad thing in a democracy). But 2016 is a long way off, and speculation about who will be the candidates, and who will win, is fun but meaningless.