The hysterical response to Donald Trump’s proposal to restrict Muslim immigration is unwarranted. Contrary to the claims of Trump’s critics, the power to suspend the admission of “any aliens or any class of aliens into the United States” is expressly reserved by statute to the president whenever the president finds that such admission “would be detrimental to the interests of the United States.” Candidate Trump is telling us that President Obama should use this power, and that a President Trump would. Despite vigorous assertions by talking heads that suspending the admission of Muslim immigrants would be unconstitutional, prior Supreme Court opinions clearly suggest that courts would reject constitutional challenges to any president’s proposed suspension of Muslim admission into the United States in accordance with U.S. law. In the leading case of Fiallo v. Bell, the Supreme Court in 1977 noted, “Our cases ‘have long recognized the power to expel or exclude aliens as a fundamental sovereign attribute exercised by the government’s political departments largely immune from judicial control.’” In upholding the authority of the government …

Donald J. Trump’s reprehensible call to bar Muslim immigrants from entering the United States tracks an exam question I’ve been giving my immigration law students since Sept. 11. Would such a proposal be constitutional? The answer is not what you might think — but it also raises the issue of what, exactly, we mean when we say something is “constitutional” in the first place. In the ordinary, non-immigration world of constitutional law, the Trump scheme would be blatantly unconstitutional, a clear violation of both equal protection and religious freedom (he had originally called for barring American Muslims living abroad from re-entering the country as well; he has since dropped that clearly unconstitutional notion). But under a line of rulings from the Supreme Court dating back more than a century, that’s irrelevant. As the court observed in its 1977 decision in Fiallo v. Bell, “In the exercise of its broad power over immigration and naturalization, Congress regularly makes rules that would be unacceptable if applied to citizens.” The court has given the political branches the judicial …