Here's the thing though. If, say, a politician who won the presidency tried to do this, he'd do it by going through the chain of command and a few months later we'd have a legal bill that restrains certain refugees and such, along with detailed instructions upon doing so, etc. It would still be bad, but it would be easier to stomach by most politicians because it had the veil of being an appropriate, legal authorization to scale back what the US would believe to be people of questionable backgrounds. That kind of law would get little pushback. You wouldn't see people marching in the streets, people outraged, people immediately pushing back, etc. You would get protests, but it would be accepted by the majority.
Here, Trump drafts an order late in the night and executes it with no clear direction, no vetting by other legal departments, and we have complete and total chaos today. Countries are immediately striking back with their own bans. People are completely blindsided by this outrage that they're immediately protesting. Politicians are caught off guard. Complete and total chaos.
The GOP would love to have someone like Trump and full control of the govt., but when he's a complete wildcard and threatens to disrupt the entire world economy and relations with the US, well, you don't just stand around and hope in four years he becomes electable again. I get the feeling there's a lot of secret GOP meetings tonight talking about how they get him the hell out of office.
I don't see this lasting four years, a year, or even the next six months.