No it won't. Trump has the most loyal supporters, and more of them. They and he aren't going anywhere.
I think Cruz is the most likely to rise, due mostly to the knockout that Bush received from Rubio last night and the set up for knock out that Trump did over the last three months.
Now that it seems like there is no chance that JEB gets elected, people will feel safe to go full bore conservative. that is Cruz. The establishment goes Rubio, Trump knocked out Lehman Brothers Board member and crony ‘out by Thanksgiving’ Kasich and leaving Rubio the only safe harbor for the GOPe and he is not near as safe as they would like since he is Conservative EXCEPT for immigration.
I see it this way. Carson falls as Cruz rises, JEB, Kasich and the other rans lose more and Rubio jumps to solid double digits. Cruz picks up the evangelicals from Huckabee, and Carson. Jumps to a virtual tie with Rubio and Carson at around fifteen & Trump continues with a strong plurality.
Trump held serve. He didn’t do anything to lose support, so he shouldn’t and if he holds at 25-35% through the winter he wins, picks Cruz as his running mate. Starts fleshing out his cabinet with some big stars, YES Rubio is a big time asset. He has a great story and a better delivery that anyone else on the stage including Cruz who is no slouch.
Regardless, anyone,save JEB, would be formidable in the General.