Suppose Trump gets the nomination; what would happen if another Republican ran as an independent? If he (she) called themselves The Real Republicans, could they pull enough Republican votes from those who are dissatisfied with Trump, plus conservative independents to mount a credible challenge to Hillary?
The way I see it, if Trump is nominated, the party is screwed. If Trump isn’t nominated, he will run as an independent, and the party is screwed. There is nothing to lose by trying a Trumpless independent run, and if Hillary stumbles, or is damaged in the Democratic primaries, could that provide an opening for an independent Republican?