The republican establishment cannot control Trump's mouth now. What makes them think they could control him if he were to be elected? I'm partly thinking along the lines of selecting justices for the Supreme Court.
...and that's a good thing.
They haven't asked themselves that yet. They will, probably, any day now. It's going to be hilarious!
If he is elected, he's still limited beyond executive orders. Congress has to legislate and confirm appointees. If elected, his head will explode from frustration 6 months in.
They cannot control him. That is why they are helping Hilliary.
She will protect the status quo and ensure nothing changes.
If she wins it will be the poor and middle class who suffer the most and the rich who prosper the most.