The two lower courts had suspended the ban.

The Supreme Court  permitted the ban to stay in effect and said "(“[A]n unadmitted and nonresident alien . . . ha[s] no constitutional right of entry to this country”)"'

 "The interest in preserving national security is “an urgent objective of the highest order.” Holder v. Humanitarian Law Project, 561 U. S. 1, 28 (2010). To prevent the Government from pursuing that objective by enforcing §2(c) against foreign nationals unconnected to the United States would appreciably injure its interests, without alleviating obvious hardship to anyone else."

A Per Curiam opinion.  

The three  'dissenters' would have overturned the lower court rulings entirely.  



https://www.supremecourt.gov/opinions/16pdf/16-1436_l6hc.pdf