"This Court has long held that an alien seeking initial admission to the United States requests a privilege, and has no constitutional rights regarding his application, for the power to admit or exclude aliens is a sovereign prerogative. See, e.g., United States ex rel. Knauff v. Shaughnessy, 338 U. S. 537, 338 U. S. 542 (1950); Nishimura Ekiu v. United States, 142 U. S. 651, 142 U. S. 659-660 (1892). Our recent decisions confirm that view. See, e.g., Fiallo v. Bell, 430 U. S. 787, 430 U. S. 792 (1977); Kleindienst v. Mandel, 408 U. S. 753 (1972). As we explained in Johnson v Eisentrager, 339 U. S. 763, 339 U. S. 770 (1950). |