If Cruz wins the nomination, then the election, the GOP-as-we-know-it is a dead letter. Cruz will ruthlessly re-organize it.
If Trump wins the nomination, then the election, he might also undertake such a move. However, Trump is first-and-foremost a salesman. And, underneath it all, a salesman wants to be liked. Consequently, Trump might make threatening noises then, after a brief confrontation, agree to bury the hatchet.
It's my firm belief that, not only must we displace the Democrats, we've got to remove the GOP/RNC leadership. We can count on Cruz to do that. Trump might...or he might not.
As likely as Sofia Vergara winning the Bruce Jenner lookalike contest. I wish him good luck. I hope his old lady get's her IMF job or whatever but he'll never be accepted and liked by enough of the American public to be elected President.