What if the ultimate nominee ends up to be neither Trump or DeSantis?
DeSantis is unlikely to win the nomination. And Trump is unlikely to win the general. This early in the game can be full of surprises.
What happens if more and more Republicans resent the idea that Donald Trump and his supporters have that he’s entitled to this nomination?
Polls at this point don't mean jack. I think more candidates could run.
With the main fight between DeSantis and Trump, I think the nominee won't be either one of them.
As for the last question, I think there are a lot of Republicans who do resent the idea that Trump and his supporters have that he is entitled to the nomination. It's one thing if he is President but he isn't so he has to earn the nomination like everyone else.