The Attorney General can refuse an alien's entry into the United States. Settled law:
Kleindienst v. Mandel, 408 U.S. 753 (1972), was a decision by the United States Supreme Court, which held that the United States Attorney General has the right to refuse somebody's entry to the United States, as he has been empowered to do so in 212 (a) (28) of the Immigration and Nationality Act of 1952.
