I'm thinking financial, if he is selling Christie this early in the game.
I can understand people making "lesser of evil" calculations when your rino is the last man standing. You don't make those calcs two years out for a man who is governor of a tiny state with no traction among conservatives whatever.
He probably fears the popular support won’t be there for a Cruz as it is so far in the pocket of the Democrats (and the devil) now.
That can change, but that is a matter of theological concern.