Nah. The establishment would knee cap Cruz in a brokered convention if they had the chance.
The delegates to the convention will be making the decision. The Cruz delegates will support Cruz.
The delegates pledged to Trump will be a variety of Trump supporters, establishment supporters, and Cruz supporters.
For example, in Texas, the national delegates will be chosen by the state convention. The selection process began at precinct conventions on election night. How many Trump supporters showed up for those, particularly Democrat cross-over voters. They have to vote for Trump on the first ballot, but will be able to vote for Cruz on rules matters, platform matters, and for Cruz after the first ballot. They can even participate in floor demonstrations for Cruz.
Will the Trump delegates switch to John Boehner, and how many ballots would it take for him to get 50%.