Carson won’t win the nomination just because he can deliver a joke and because some Republicans need to say to Democrats “our black is better than your black”. It’s not enough. Let’s see how he holds up when he gets tested.
Also, I suspect the GOPe (i.e., the money men) figure that he’s enough of a political novice that he can be controlled (at least compared to Trump). That they (the GOPe) are warming to him, a total novice, just shows how bad things are going for them.
The key for the GOPe is to hype Carson up just enough to win Iowa and embarrass Trump out of the gate. There’s a huge chance Carson can win it as the kind of social conservative Iowans love to follow Huckabee and Santorum.
Carson has no chance in comparatively non-religious New Hampshire. That is where they’d have to find a different strategy to take down Trump. But if they can load all their firepower on him in NH and win, then Trump’s sunk. Trump will win South Carolina just as Gingrich did and it will be the kiss of death as it won’t carry elsewhere except in a few of the reddest states.