They are going to knee cap him. Sorry to break it to you. Cruz will never be the nominee. They would without hesitation substitute Ryan.
Trump.... They fear him.
The "They" you refer to are the delegates. Here in MA we vote for MOST of them later this month.
Yes, the GOPe will have a few "superdelegates" (Here in MA its about 15). But, over 40 delegates will be committed to the winner on the 1st ballot (Trump from MA), then released... and they by and large will be Trump/Cruz-minded delegates. These delegates will retain rule-40, thus eliminating ANY possibility of a Kasich or Ryno. The second ballot WILL BE either Trump or Cruz.
I will vote for Trump or Cruz as the Nominee.
If it should be Ryno, ... if it should be anybody other than Trump/Cruz... well, might have to leave the GOP.