Will you stay home if they screw both Cruz & Trump or will you march blindly to the polls and pick Ryan?
It may be irrelevant who they push. A lot of the delegates are handpicked by the candidates. And a lot of other ones are likely to be conservatives who won't go along with the national establishment. As reported by Newt Gingrich who probably knows the way conventions work far better than you or I, it will be very, very hard for the establishment to deny two candidates who together account for around 80% of the delegates.
Unlike stupid idiots who give the elections to Democrats to ruin our country just because they are pouting about their personal Republican choice not winning, I would go to the polls FAR FROM BLINDLY, but HOLDING MY NOSE if an establishment Republican got the nomination.
Hell, I'd have to HOLD MY NOSE just as much for Trump, because even though I personally can't help but like him a little and enjoy the havoc he creates, I don't agree with 25% or so of his stated policies, don't trust him to implement the ones I agree with, and most of all because he's a self-absorbed unethical bully.
I'd rather put a bullet between John Kasich's eyes than vote for him, but I'd still vote for him to stop Hillary or whatever other left-wing stooge the Dem's put up when she's indicted. That answer your self-righteous question about marching blindly to the polls well enough?