For well over a century, the border has been a legal black hole that enables the U.S. government to exclude non-citizens from entering the country—even for reasons that are discriminatory with respect to race, religion, or viewpoint. In 1892, the Supreme Court declared that, for non-citizens who have not been admitted to the United States, “the decisions of executive or administrative officers, acting within powers expressly conferred by Congress, are due process of law.”1. Nishimura Ek...