This is one of the US president Duties. To serve and protect the People of America. American people, citizens of the USA. You know I always get a kick when the leftest Democrats and these Politically correct Judges say ,Trump's ban is "Unconstitutional" because of what he said during the campaign, of it being a religious Ban! Poppycock!
This is a First!  He was not POTUS yet! The ruling to block Trump's Travel ban ,thus  becomes irrelevant! 
And may I remind y'all, our president also has the right to build "The Wall" without congress's permission,this is also mandated in the US presidential duties. "To Protect it's borders from foreign and domestics threats. And yes,we all know Congress controls the purse.
Lastly, for those of you who think this travel Ban is "Unconstitutional" you are wrong! The right of  the US Constitution is reserved only for the citizens of the U.S. of A ,not citizens of another country.
Simple as that! IMUA!