On Tuesday, the Supreme Court will hear oral arguments about one of the cruelest immigration policies introduced by the Trump administration—a policy that closed the border to tens of thousands of people who have fled persecution. The Migrant Protection Protocols (MPP) policy, first implemented in 2019, forces people who seek asylum in the U.S. to remain in Mexico while their cases are decided, allowing them in only for periodic court hearings. In practice, the policy traps vulnerable people in dangerous conditions in Mexican border cities, making it all but impossible for them to present their case to a judge.

As civil rights lawyers who represent individuals trapped by MPP, we have seen how it subjects refugees to homelessness, extreme poverty, and violence, and how it eviscerates any semblance of due process in the asylum system by obstructing access to counsel and critical evidence our clients need to prove their claims.

In keeping with his campaign promises, President Biden ended MPP shortly after taking office. But last year, Texas and Missouri sued the administration, arguing MPP should be reinstated because the decision to end it was arbitrary and capricious under the Administrative Procedure Act. The two states soon won a nationwide injunction from a district court judge that required the administration to restart MPP along the entire southern border.

Does it sound odd that two states—one of which has no international border—got a single district judge to alter the entire country’s federal immigration policy? It should. Prior to 2014, states did not even ask judges to do this. But that changed in 2015, when a judge in Texas issued a nationwide injunction against an Obama-era program that would have protected parents of U.S. citizens and permanent residents against deportation. The trend continued under Trump, as Washington and Hawaii won similar nationwide orders blocking the first two versions of the Muslim Ban, other states stopped the memo rescinding DACA, and three northeastern states convinced a judge in Manhattan to stop the “public charge” rule (which excluded immigrants who are “likely at any time to become a public charge”). In other words, the trend, which began less than a decade ago, has worked to stymie the federal government’s immigration policies both when those policies expanded and contracted immigrants’ rights. It can cut both ways.

Under the Biden administration, the practice of single district judges setting nationwide immigration policy in cases filed by states has exploded. In just one year, states have won nationwide injunctions blocking the President’s moratorium on deportations, Texas v. United States, 515 F. Supp. 3d 627 (S.D. Tex. 2021), prosecutorial discretion policies (three times), see, e.g., Arizona v. Biden, No. 3:21-cv-314, 2022 WL 839672 (S.D. Ohio Mar. 22, 2022), his attempt to reverse Trump-era border policies, including the expulsion of children under Title 42, Texas v. Biden, No. 4:21-cv-0579-P, 2022 WL 658579  (N.D. Tex. March 4, 2022), and in the MPP case that’s now before the Court, Biden v. Texas, No. 21-954. Just in the past couple of weeks, states have asked a court to enter a nationwide order halting the Biden administration’s attempt to end the Title 42 order, which suspends the right of people fleeing persecution even to ask for asylum at the border. Arizona v. CDC, No. 6:22-cv-885, Plaintiff States’ Motion for Preliminary Injunction (W.D. La. April 14, 2022).

Last month, our Center for Immigration Law and Policy at UCLA School of Law filed an amicus brief seeking to constrain this judicial practice. Our brief to the Supreme Court argues that, whether or not the Court agrees with the merits of Texas and Missouri’s claims, the justices should restrict the lower court’s injunction to the states of Texas and Missouri, rather than letting a single judge set nationwide policy.

We expect our position to attract some unusual allies. Although Justices Thomas and Gorsuch are not known for their pro-immigrant views, both have strongly criticized nationwide injunctions as likely unconstitutional. Justice Thomas’s concurrence in Trump v. Hawaii, for instance, argued that the equitable authority of the federal courts is limited to the powers exercised by the English Court of Chancery in 1789, and those powers did not include authority to “provide relief beyond the parties to the case.” Trump v. Hawaii, 138 S. Ct. 2392, 2425, 2427 (2018) (Thomas, J., concurring) (citing Grupo Mexicano de Desarrollo S.A. v. Alliance Bond Fund, Inc., 527 U.S. 308, 318 (1999)). Justice Thomas recognized that the common law countenanced “bills of peace” and other exceptions to the default rule that only parties’ rights may be adjudicated, but he concluded that “these ‘proto-class actions’ were limited to a small group of similarly situated plaintiffs having some right in common.” Id. at 2427 (citing Bray, Multiple Chancellors: Reforming the National Injunction, 131 Harv. L. Rev. 417, 425 (2017)). If these two Justices maintain their expressed views, one would expect them to refuse to affirm virtually any injunction that a court applies nationwide to non-parties merely because the Court believes federal immigration policy should, in general, be uniform.

Our brief does not advance an argument as broad as that pressed by Justices Thomas and Gorsuch. But we do contend that nationwide equitable relief should be rare in cases that do not involve certified nationwide classes or national organizations. And, no matter who seeks a nationwide injunction, such relief must always be proportionate to the alleged injuries and crafted carefully so as not to burden the interests of non-parties more than necessary. That principle is reflected in the longstanding requirement that courts must consider the public interest when deciding whether to grant an injunction at all. See generally Weinberger v. Romero-Barcelo, 456 U.S. 305, 312 (1982).

The MPP case perfectly illustrates why courts should be far more reluctant to grant nationwide injunctions on behalf of individual states that challenge federal immigration policies. The district court justified altering policy along the entire Southern border—including in New Mexico, Arizona, and California (which are not parties to this case)—because Texas and Missouri claimed they would suffer economic harm if people who enter through other states later move to theirs and, once there, obtain driver’s licenses or public benefits. But the court had no way of knowing how many (if any) people seeking asylum at the border in, say, California, would ever move to Texas or Missouri and later cost those states money. Yet by issuing the injunction, the court required MPP to resume in California, even though that state strongly disagrees with the lawsuit.

As our brief explains, the law does not permit this. Even if the district court correctly granted relief to the states suing the federal government, a position with which we disagree, its injunction was obviously disproportionate to the harm alleged insofar as it required the federal government to resume operation of MPP in California, Arizona, and New Mexico, even though those states were not parties to the suit. To justify that strange result, the court concluded: (1) that individuals who would otherwise have remained in Mexico under MPP would be paroled into the United States once MPP was terminated; (2) that some of those individuals would move from the state in which they entered to Texas or Missouri; and (3) that, once there, those individuals would apply for and obtain public services (like driver’s licenses) from those two states.

The court’s reasoning failed to account for an obvious difference between enjoining the MPP termination only in Texas and enjoining it elsewhere along the Southern border. Where individuals enter the United States through Texas and reside there, the alleged economic harm to that state is directly traceable to the challenged federal policy. But the harm arising from such individuals entering other states occurs only if they later move to Texas or Missouri and then obtain public services there. Aside from the lack of evidence to support it, that theory of harm is far too attenuated, under basic equitable principles of proportionality, to justify an injunction in states that are not party to the case. As Judge Sutton from the Sixth Circuit recently explained when staying yet another nationwide injunction issued on behalf of a handful of states challenging a federal immigration policy, “At a minimum, a district court should think twice—and perhaps twice again—before granting universal anti-enforcement injunctions against the federal government. Even if it turns out that the three States in this case are entitled to relief, it is difficult to see why an injunction applicable only to them would not do the trick.” Arizona v. Biden, No. 22-3272, 2022 WL 1090176, at *11 (6th Cir. Apr. 12, 2022).

Thus, the district court’s ruling in Biden v Texas should have (at most) bound the federal government only in Texas and Missouri, in keeping with the court’s modest role as one district court granting relief to the parties before it. And lest you think it strange to imagine a non-uniform border policy, having practiced on the border for years we can assure you that in fact it is the norm. MPP provides a perfect example: since its inception, the policy has been implemented differently across different parts of the border. This is consistent with how other rules governing important aspects of the immigration system differ based on splits between circuits and other factors. The law governing parole procedures for people seeking asylum, green card eligibility, bond hearing procedures, and various other important immigration rules have varied from one region to another for years. In those cases, as here, there is no burning need for uniformity sufficient to justify one heavy-handed, if not draconian, order to govern the whole country.

A Supreme Court decision limiting the injunction in Biden v. Texas would save thousands of lives. It could, in addition, resonate far beyond this case, and even this administration. Sooner or later, the shoe will be on the other foot, as it was with Trump before Biden, and Obama before Trump. None of us should want to live in a country where a few states can so easily dictate immigration policy for the whole nation. Limiting the extent to which judges in Texas dictate federal immigration policy that binds California, and vice versa, could also help reduce the temperature—even if only slightly—in the heated Red/Blue battle that has come to define so much of our immigration politics in the last decade.