Can US Customs and Border Protection refuse any non-US citizen to?
The article does not say that the aliens were denied admission without being given a reason and includes no statement from CBP. What it says is that a group of 9 Chinese nationals with visas to study at Arizona State University were denied admission and the university does not know why. To be blunt, the CBP owes no explanation to a university, an employer, the press or any other third party about their decision to deny admission to an alien. The aliens may seek answers either directly or through their attorney at the U.S. embassy or consulate in their home country.