So who do they pick? Good luck. Trump isn't an accident. His ascendence is tied to Republican voters who became a sort of frankenstein's monster of the GOP elites' own creation. Weened on decades of victim-speak, impossible goals, over-primed lust for revenge against various domestic bad guys and outsiders and perverts and all the rest, they finally rebelled and chose someone who at least said he could follow through on the political snuff films they see on Breitbart, Newsmax, WorldNetDaily and the rest.
So who wants to replace Trump? Cruz certainly, someone who is probably too conservative for a national electorate and wildly reviled as someone actually less likable than Trump. Pence? A right-wing non-entity who his own state's Republican party didn't want anymore. Ryan? Maybe but he's probably too smart to put himself through that. Jeb or Rubio, who voters mammothly rejected?
The real story is that it reopens all the structural divisions in the GOP itself, precisely what the primary process was unable to grapple with successfully. Only now it gets hashed out not with any input from voters but literally behind closed doors by literally a group of Republican insiders and elites. And all this with 90 days before election day? That should go amazingly well.
This doesn't even get into the logistical and in some cases legal obstacles to changing the name on the ballot once you get into September.
It's all like a fevered reverie of contested convention and all the other denial nonsense we've seen since last fall. The truth is that as bad as the Trump situation is, I think most members of the RNC, high level Republicans would look at that scenario and say, "Let's stick with Trump."