It sure seemed that the other candidates wanted to win the nomination very badly. Did someone go to them and say "Uh, hey, we are going to throw this election to Candidate X because we are going to lose anyway, so please just say something stupid so you lose the primary and drop out".

Why would the GOP want to give a chance for the Democrats to win, to be successful, lively and popular?

McCain is the GOP's best chance for a victory. They will try to win. Personally, I think a lot of people will not vote for a black man and the election will be close.