It's gonna happen. It's perfectly legal for the RNC to just change the rule, allowing delegates to vote for whoever they want. A couple hundred Trump delegates will bail the moment they get permission.
Then it's wide open. Paul Ryan? Cruz? Ben Affleck or Tom Brady? LOL!
Trump is intentionally underachieving so they'll bounce him - he won't fight that hard.
Honestly, if it was anyone else, the Republicans probably win.