the muslim ban is and was promised to be temporary. that doesn't make it less unconstitutional, but the fact that it comes with a sunset clause gives it a level of legitimacy beyond it's unconstitutionality.
i'll remind you again that i'm a canadian. and, i actually don't know what the precedent for this is in the united states. but, in canada, the sunset clause would get him off of the hook.
see, in canada, the law is allowed to be unconstitutional so long as it is justified, and limited in scope (i'm not using legal jargon, but you can google this quickly). the question of whether it's justified rests on the legal premise that the parliament gets to decide this (i suppose the parallel would be in the executive branch, here) and not the court. the court can pull out a factual error, but it has to ultimately defer to the will of the people.
so, he wouldn't be allowed to pass a permanent ban. that would be wiped out. but, the way he presented the ban is that it is temporary and for a reason that he claims is valid. a court here would agree that it's unconstitutional, but would not overrule it for those reasons.
i again need to suggest that this is a smoke & mirrors tactic. you're being distracted. why?