The GOP has four five choices:
1. Nominate Rubio
2. Nominate Bush
3. Nominate Paul
4. Nominate Kasich
5. Lose
FTFY
I've got to tell you, I'm not so convinced John "God Wanted me to Expand Medicaid" Kasich could win a general election. I think his lack of diversity in his Ohio cabinet will be used against him in a major way in a general election. Additionally, if you think Jeb stumbled on Iraq, Kasich went from urging an invasion in 2002 to now saying he never would have gone in.
Absolutely no one who would ever consider voting for any Republican is going to vote against Kasich because "his cabinet was too white." In fact, if the media or the Clinton campaign attempted to use that idiotic line of attack (which I doubt), it would be more likely to backfire and help Kasich than it would be to cost him the election.