Where do the "bigots and religious nuts" go? I think you underestimate how entrenched lower-educated White trash is in local GOP machinery; for all their faults, the Democrats are at least organized and have more "smart people" sweeping the loonies under the rug come election time. In the GOP, they are front and center.
Honestly, if not for a few weirdo economic redistribution and climate change fantasy types, Wall Street and corporate America would be totally in the Democratic camp. When that happens, you are left with Rednecks who make less than $60k a year and people who own Ace Hardware franchises as your "power base". You need more than a irrational fear of brown people to win a national election.....
If Trump is out, I would hope the Bigots would disperse among other candidates and thus bigotry would not be the defining factor of the Republican nominee.
I wish the Republicans would force the bigots out, let them drift in the wilderness, but they get a strong voice because without them the GOP would have a much harder time winning.