Once again, let me remind you that the Muslim ban isn't about banning Muslims, or national security, or even immigration. Trump doesn't care about any of that. It's only a wedge issue he uses to excite voters and piss off opponents, just like abortion, guns, "lock her up", "build the wall", "repeal and replace", etc. They are tools used by the rich and powerful to convince the poor to vote against their own self interest.
The only thing that Trump really cares about is making himself rich. In order to profit, he needs power. All of these other issues are just ways to get power, to him, not ideologies he actually cares about. He literally laundered money for the Russian mob in order to get rich, you think he won't also send some crazy ass tweets?
The longer everyone argues about the details of the Muslim ban, the more power he amasses. He just needs to be in the spotlight, so it doesn't really matter if the ban stands or is repealed, or works or doesn't work. Doesn't matter. The only point is to command the news cycle and divide the nation from itself.
Racism is a very effective tool in that game.