More and more Repubs are getting fed up with this loose cannon. At some point they will abandon him for someone they can control, like Pence. He's already given them a pro-life judge, rolled back environmental protections, and lowered taxes for the rich. There's not much more he can deliver, so his usefulness might be waning.
The only thing holding many of them back now is their fear of being primaried.
The only thing holding many of them back now is their fear of being primaried.