	Introduction

In precedent stretching back to the Chinese Exclusion Case of 1889, the Supreme Court has held that Congress possesses "plenary power" to regulate immigration. The Court has determined that the executive branch, by extension, possesses unusually broad authority to enforce laws pertaining to alien entry, and to do so under a level of judicial review much more limited than that which would apply outside of the exclusion context. The scope of the federal government's power to exclude aliens is at the forefront of litigation concerning two successive executive orders (the second revising and replacing the first) issued by President Donald Trump that, in their revised form, seek to deny entry temporarily to foreign nationals from six predominantly Muslim countries and to all refugees, subject to limited waiver. The litigation has threshold issues, however, such as questions of mootness and standing, that may well prevent the Court from reaching the merits, particularly following the issuance of a presidential proclamation superseding and somewhat modifying some of the entry restrictions at issue in the case. Second, the report analyzes the extent to which the constitutional and statutory rights of U.S. citizens limit the exclusion power under the "facially legitimate and bona fide" test of Kleindienst v. Mandel . The report applies the principles of the Supreme Court's immigration jurisprudence to the two primary claims that U.S. persons and entities have pressed against the President's revised executive order in the "Travel Ban" litigation: (1) that the revised order violates the Establishment Clause; and (2) that the revised order violates the Immigration and Nationality Act (INA). The Supreme Court has since relied upon these cases for the proposition that excluded nonresident aliens cannot state legal claims with respect to entry. The question about the extent to which U.S. citizens can challenge an alien's exclusion, on the other hand, has occupied the Court in three important cases since 1972: Kleindienst v. Mandel , Fiallo v. Bell , and the splintered Kerry v. Din . Under the rule that these cases establish, the government need only articulate a "facially legitimate and bona fide" reason for excluding a nonresident alien or class of aliens in order to prevail against an American citizen's claim that his or her constitutional rights have been violated by the exclusion. The case produced the test that continues to govern claims that the exclusion of an alien violates an American citizen's constitutional rights:
[P]lenary congressional power to make policies and rules for exclusion of aliens has long been firmly established.... We hold that when the Executive exercises [a delegation of this power] negatively on the basis of a facially legitimate and bona fide reason , the courts will neither look behind the exercise of that discretion, nor test it by balancing its justification against the First Amendment interests of those who seek personal communication with the applicant. Despite the relatively clear picture of the scope of the Executive's exclusion power drawn from Mandel , Fiallo , and Din , three unresolved issues warrant discussion: (1) whether the Executive possesses inherent exclusion power, as opposed to solely statutory-based power; (2) the extent to which U.S. citizens or entities may challenge an alien's exclusion on statutory grounds; and (3) the extent to which the Constitution limits the Executive's application of broad delegations of congressional power to make exclusion determinations. At least one pre- Mandel Supreme Court decision states that the Executive does possess inherent authority to exclude aliens. Supreme Court precedent offers limited guidance as to whether such statutory claims are cognizable and, if so, what standard of review should govern them. The Supreme Court also limited the lower court injunctions to allow the government to apply EO-2's entry restrictions against aliens who do not have a "bona fide relationship" to a person or entity within the United States. The Supreme Court likely will not address the underlying question about the outer limits of the executive power. The Court could dismiss the government's appeals in the Travel Ban cases as moot or reject the plaintiffs' claims for lack of standing rather than decide them on the merits; or, maybe most in line with its approach in prior exclusion cases, the Court could decide the merits of the plaintiffs' claims in a way that does not require it to define the boundaries of the Executive's power, such as by rejecting the claims under domestic Establishment Clause jurisprudence.
The Supreme Court has determined that inherent principles of sovereignty give Congress "plenary power" to regulate immigration. The core of this power—the part that has proven most impervious to judicial review—is the authority to determine which aliens may enter the country and under what conditions. The Court has determined that the executive branch, by extension, has broad authority to enforce laws concerning alien entry mostly free from judicial oversight. Two principles frame the scope of the political branches' power to exclude aliens. First, nonresident aliens abroad cannot challenge exclusion decisions because they do not have constitutional or statutory rights with respect to entry. Second, even when the exclusion of a nonresident alien burdens the constitutional rights of a U.S. citizen, the government need only articulate a "facially legitimate and bona fide" justification to prevail against the citizen's constitutional challenge.
The first principle is the foundation of the Supreme Court's immigration jurisprudence, so well established that the Court has not had occasion to apply it directly in recent decades. The second principle, in contrast, has given rise to the Court's modern exclusion jurisprudence. In three important cases since 1972—Kleindienst v. Mandel, Fiallo v. Bell, and the splintered Kerry v. Din—the Court applied the "facially legitimate and bona fide" test to deny relief to U.S. citizens who claimed that the exclusion of certain aliens violated the citizens' constitutional rights. In each case, the Court accepted the government's stated reasons for excluding the aliens without scrutinizing the underlying facts. This deferential standard of review effectively foreclosed the U.S. citizens' constitutional challenges. Nonetheless, the Court refrained in all three cases from deciding whether the power to exclude aliens has any limitations. Particularly with regard to the executive branch, the Court left an unexplored margin at the outer edges of the power.
In March 2017, President Trump issued an executive order temporarily barring many nationals of six Muslim-majority countries and all refugees from entering the United States, subject to limited waivers and exemptions. This order replaced an earlier executive order that a federal appellate court had enjoined as likely unconstitutional. Upon challenges brought by U.S. citizens and entities, two federal appellate courts determined that the revised order is likely unlawful, one under the Establishment Clause of the First Amendment and the other under the Immigration and Nationality Act (INA). The Supreme Court agreed to review those cases and, for the meantime, has ruled that the Executive may not apply the revised order to exclude aliens who have a "bona fide relationship" with a U.S. person or entity. In reaching this interim solution, the Supreme Court considered only equitable factors and carefully avoided any discussion of the merits of the constitutional and statutory challenges against the revised order. Even so, the Court's temporary restriction of the executive power to exclude nonresident aliens abroad is remarkable when compared with the Court's earlier immigration jurisprudence.
The merits of these so-called "Travel Ban" cases raise significant questions about the extent to which the rights of U.S. citizens limit the executive power to exclude aliens. It seems relatively clear that, under existing jurisprudence, the "facially legitimate and bona fide" standard should govern the Establishment Clause claims against the revised executive order. However, Supreme Court precedent does not clarify whether that standard contains an exception that might permit courts to test the government's proffered justification for an exclusion by examining the underlying facts in particular circumstances. Nor does Supreme Court precedent resolve whether the standard governs U.S. citizens' statutory claims against executive exercise of the exclusion power, or even whether such statutory claims are cognizable. The outcome of the Travel Ban cases would likely turn upon these issues, if the Supreme Court were to decide the cases on the merits rather than on a threshold question such as mootness (a key issue in light of a presidential proclamation modifying the entry restrictions at issue in the cases).