This doesn't matter to Trump.  He will push as far as he can get away with.
The border control has already started.  Extreme vetting is here.
Canadians being turned away from crossing the border, Mexican illegal crossings being intercepted at a rate of 40% less than last year due to terrified Mexicans no longer willing to cross,  ICE increasing it's arrest and deportation of illegals.  
One way or another, this will get past the courts, but in the meantime, really, how many people travelling from the 6 countries are going to get through without EXTREME VETTING?  Welcome to the new, secure America.