When was the last time the GOP had a contested convention? How many decades ago was that? It is NOT the norm.
What does that have to do anything.
The purpose of the primary is to identify a candidate that can unify the party for the general election, and a candidate demonstrate he can do this by getting the majority of delegates to vote for him.
And if Trump can’t accomplish this, that means we don’t have such a unifying candidate.
Trump supporter should be focused on getting him over 50%, nothing turns off the supporters of other candidates and counter the object of unification than their strident declaration that their candidate should get the nomination no matter how the primary voters vote from here on out.