"Is there anyone on stage—can I see hands—who is unwilling tonight to pledge your support to the eventual nominee of the Republican Party and pledge to not run an independent campaign against that person? Again, we’re looking for you to raise your hand now, raise your hand now if you won’t make that pledge tonight.”Only Trump raised his hand.
Because we know that even if Yeb doesn't run third party when Trump wins---and at this rate, he would win the GOP nomination by April---you know that NONE of these guys, except Carson and Cruz---would lift a finger to support Trump.
So the premise of the question is disgusting, and the fact that only one candidate was honest is even more disgusting.
Trump will string this out and play this game til he wins the nomination, then challenge the rest of these bozos to act like men and actually support him.