When a distance runner suspends his race, he is no longer going to finish.
Politics is weird.
How about I say, “The only 3 still competing.”
No, my point is that once you get to a contested convention, they are all competing. Ryan has said so. Priebus has said so. If you don't have 1,237, it is up to the convention. Rubio is not releasing his delegates.
If you adhere to rule 40b, then only Trump and Cruz are eligible to compete. I suspect that the rules committee that meets a week before the convention begins will seek to modify it. Each change must be approved by a majority of the total delegates. Most of them are GOPe types and will probably agree to a change that allows others to compete as well.
Cruz and Kasich are the stop Trump candidates. They have no way of reaching 1,237 thru the primary process. Once Trump is defeated on the first ballot, if we get to a contested convention, then it is a free for all. Trump will be cast aside and the horse trading will begin. It is imperative that Trump win on the first ballot, otherwise we will get a GOPe candidate. If Cruz were really an outsider, he would have dropped out after FL.