What if the gope demonstrably cheats to shave enough delegates to keep it under? Would turnabout be fair play?
If Trump has 1237 delegates and does not get the nomination, then the GOP deserves whatever happens. If they change the rules to deny Trump delegates he has earned then they deserve whatever happens. But barring that, if Trump goes into the convention with less than a majority of delegates, it will be up to him to try to persuade enough delegates to vote for him on subsequent ballots to give him the majority, or he won't be the nominee.