They are lockstep with him. They fear his right wing base. GOP really fears a strong right wing 3rd party. American Independent Party, George Wallace or "Reform" Part of Ross Perot. Trump is a loose cannon, nobody knows what he'll do. He has a large following. He's dangerous and they are not going to mess with him. They're pussies.

Yes but they are not people, they are politicians.

I believe they're afraid that his retaliation will be exposing their dirt. Trumps is full if rage. They're silence is to save themselves.