Carson and Bush need to exit after tonight if the numbers we predict come to fruition. Carson's votes were first thought to be going towards Cruz in large part, but after Iowa Cruz has probably screwed the pooch on that one, we'll have to wait and see. He needs most of Carson's voters if he's to have a chance once the field goes down to the big 3 (and Kasich). Most of Bush's voters go to Rubio, so he needs Mr. Bush to drop out after tonight so he can start winning come Super Tuesday. I think this is the point in the race where we'll see the tide turn and Rubio will be the nominee in the end.
I agree that Bush needs to go as well and the only reason that I didn't include him among those who will drop out is because he has a money advantage over other low-tier candidates. My guess is he will call it quits after super tuesday. That said, it would certainly help to un-muddy the waters for the Republican nomination.
not true, the donors are jumping ship after a poor showing tonight (that's the word on the street)....so he won't have the money to continue