So the solution is to run another guy against Donald, split off enough votes to send it to a second ballot, in which the entire GOP as a block will dump Trump and Cruz, and re-nominate the failed candidate from last time, Romney.
Is that about right?
Because that sure seems to me, to be what is unfolding.
That cannot happen unless either Trump's delegates or Cruz's delegates bail on their candidate and (1) vote to change the eligible candidate rule, and (2) then vote for one of the failed candidates.
Under the current GOP Convention Rules, the only eligible candidates are Trump and Cruz, since they are the only candidates who have won a majority of delegates in more than eight states (Rule 40). There is no reason either Trump's or Cruz's delegates would want to change that, since it would only ensure that their candidate would lose the nomination.
So if neither candidate gets the nomination before the convention, the nomination will come down to whichever candidate can win over most or all of the delegates that were pledged to one of the failed, ineligible candidates.