He knows that it would put Madame Benghazi in the oval office and that is his scare 'em negotiating tactic. The Donald knows how to do it. He basically told them, "I don't have to be president. I'm rich and comfortable but if you don't want Hillary to be your boss and to lose the entire Senate and House, don't mess with me."
We were going to have Hillary anyway. The base is not going to vote GOPe. Period.