The National Injunction

Introduction

A federal judge may conclude that the government has acted unlawfully. The more difficult issue is what the judge may do about it. Traditionally, courts have provided remedies that applied to the particular parties in the litigation. Thus, if the government's action unreasonably burdens a single plaintiff, the courts may be able to provide relief that protects that plaintiff's interests. But federal courts have increasingly issued nationwide injunctions, which prevent the government from taking an action not only against the plaintiffs in a given case, but also against every person in the country

The debate over the authority of federal courts to issue such relief has become one of the most important issues in modern federal jurisprudence.

The Supreme Court has recently considered the issue in Trump v. CASA, Inc., 606 U.S. 748, 762-79 (2025). The Court held that federal courts have no general authority to issue universal injunctions beyond what is necessary to provide complete relief to the plaintiffs in a given case.¹ The Court did not totally prohibit such relief, but it made clear that federal trial courts have extremely limited power to provide relief that affects every person in the country in a case brought by individual plaintiffs.¹

The issue before the Court raises a difficult constitutional question: when a federal court invalidates a governmental policy, how far should the court's power to restrain the President reach?

The Nature of an Injunction

An injunction is an order from a court directing a party to refrain from or perform a certain activity. The power to issue injunctions generally arises from the court's equity jurisdiction. Equity developed in part because common law remedies were too limited to address certain harms.² Consequently, an injunction is not a remedy that a court may issue simply because the court determines that one party has "won" the lawsuit. Instead, the court must determine that there is some connection between the defendant's wrongful activity and the relief the court orders. This principle becomes particularly difficult to apply when the defendant is the federal government.

Assume, for example, that five plaintiffs successfully challenge a regulation and show that the regulation is unlawful. A federal court could issue an injunction preventing the government from applying the regulation to those five plaintiffs. But why should the court issue a nationwide injunction that prevents the government from applying the regulation to anyone?

Proponents of nationwide injunctions argue that a court may be justified in issuing such relief when a challenged governmental policy is unlawful in its entirety. Detractors of nationwide injunctions respond that such a remedy gives a single district court judge far too much power.

The Development of Nationwide Injunctions

Nationwide injunctions have become increasingly common in the twentieth and twenty-first centuries, particularly in litigation concerning allegedly unlawful federal regulations and presidential policies.³

Such injunctions can have significant benefits. A federal court may be able to provide relief that prevents the President from immediately enforcing a challenged policy against some federal citizens while that policy is fully considered by the courts. If a court does not issue a nationwide injunction, the President could enforce the policy against all Americans at once or in a haphazard manner, depending on the number of courts that review the policy. The ability to issue a nationwide injunction could prevent this result. Courts generally act more predictably than legislatures and executives, so a nationwide injunction could provide much-needed uniformity in the face of a controversial policy decision.

The Article III Problem

Article III of the Constitution provides that federal courts have jurisdiction in "Cases" and "Controversies."⁴ Most importantly, this means that federal courts do not act as general repositories of legal authority; they exist to decide specific disputes between actual parties.

When a plaintiff sues the federal government, the plaintiff seeks relief because the government has harmed the plaintiff or will harm the plaintiff in the future. Thus, when a court issues an order affecting every person in the country, the result is something like a judgment in favor of people who were not parties to the litigation.

Harvard Law Review commentators have argued that this is a problem of "aggregation." A court essentially confers a benefit on a group of people who were not before the court without following the procedural safeguards that apply when a court acts on behalf of everyone who is injured.⁵

That concern was the primary basis for the Supreme Court's recent decision in Trump v. CASA, Inc..¹

The Trump v. CASA Case

The 2025 case concerned challenges to the Trump administration's policy statement concerning birthright citizenship. Several lower courts issued nationwide injunctions preventing the government from implementing the policy.¹ The administration petitioned the Supreme Court to review those injunctions and the Court agreed to hear the case. The administration argued that district courts do not have jurisdiction to issue universal injunctions. The Court agreed. This essay will explain why.

Writing for the majority, Justice Barrett stated that the federal Judiciary Act does not give federal courts the power to issue relief more far-reaching than traditional equity principles would allow.¹ The Court reasoned that an injunction should not generally extend beyond the relief necessary to cure the harm to the plaintiffs who brought the suit.

The Court's holding has important implications for the separation of powers. It shifts the focus of litigation from whether a given governmental action is unlawful to what remedy a federal court may issue when it concludes that a policy violates the Constitution or a statute.

It is worth emphasizing that a plaintiff may always win the lawsuit but receive less relief than the plaintiff requested initially.

The Class Action Alternative

Perhaps the best argument in favor of limiting universal injunctions concerns the availability of an alternative form of relief: the class action.

Fed. R. Civ. P. 23 allows any plaintiff who meets certain requirements to ask the court to certify a class of plaintiffs who were not parties to the initial litigation and to receive the same judgment as the original plaintiff. This rule has several important advantages over a universal injunction. First, the court must expressly find that the case meets the requirements of Rule 23 before it may issue any relief. Second, the plaintiffs in the lawsuit must adequately represent the people who are actually injured by the government's action. Finally, these plaintiffs may not receive a judgment unless the court finds that they share a common interest with absent class members. Harvard Law Review commentators have argued that the class action could provide an appropriate vehicle for universal relief when a governmental policy injures many people.⁵

The class action approach has one major benefit: It preserves a clear distinction between cases that involve only one plaintiff and those that involve many.

If a single plaintiff wishes to obtain a universal injunction, then that plaintiff should have to navigate the complexities of a class action lawsuit from the very beginning.

The Problem With Narrow Relief

Limiting the relief that a plaintiff may receive in a given case also has costs. Imagine a situation in which the federal government issues a regulation that affects all Americans. Assume further that the regulation is unlawful but that a federal court's narrow injunction only prevents the government from applying the regulation to the plaintiffs in the case. In that situation, the government would be free to apply the regulation to everyone else in the country. This outcome would likely require thousands or even millions of citizens to file identical lawsuits against the government. The result would be wasteful and could also cause great confusion if different courts issued different rulings about the legality of the same regulation. This is sometimes called a "patchwork" of competing and inconsistent court decisions.³

Nationwide injunctions could prevent this result immediately. But they come at the expense of giving too much power to a single district court.

District Judge Power and Uniformity

This concern goes to the heart of the debate. There are more than 600 authorized district judgeships in the United States.⁷ That means there are more than 600 district judges who could potentially issue nationwide injunctions. Under current law, each of these judges has the power to modify or completely invalidate a national policy, at least in theory. Critics of nationwide injunctions argue that this gives every citizen an incentive to forum shop until they find a judge willing to issue a nationwide injunction.³ In other words, citizens will bring lawsuits in whatever districts have judges who are willing to issue injunctions against the national government. Proponents of nationwide injunctions respond that the location of a given district court should be irrelevant to the ability of a plaintiff to obtain a judgment against the federal government. Thus, proponents argue, if a national policy is unlawful, then it should be unlawful everywhere at once. A single district court judge may not be the best arbiter of the nation's laws, but advocates argue that judges should still have the power to issue nationwide injunctions.

Both sides of this debate raise valid concerns. On the one hand, there is a great risk that a federal court will issue a too-narrow injunction and allow a broadly unlawful policy to continue. On the other hand, allowing a single district court to decide that a policy is unlawful seems like an extreme dilution of the separation of powers.

What Comes Next

The nationwide injunction debate will continue long after Trump v. CASA, Inc. leaves the courts. This decision does not directly change the availability of class actions or nationwide relief, although it may increase the use of class actions as a result of the greater scrutiny of injunctions.¹⁵ Instead, the decision places new restrictions on the ability of a court to issue relief beyond the needs of the plaintiff.

This change will have important real-world effects. In particular, courts will be forced to explain why a given injunction extends beyond the needs of the plaintiff. This could lead to a significant increase in the number of class action lawsuits and affect the litigation strategy of any lawyer who wishes to challenge a national policy. Additionally, because the

CASA decision only applies to the federal government, there will continue to be a significant number of cases in which a district court may issue an injunction against a state or a private defendant.

There has long been a debate about whether courts should decide cases involving many plaintiffs as if they only involve the named parties. The Trump v. CASA decision changes this debate by making it much more difficult for a district court to issue a remedy that goes beyond the needs of the plaintiff.

The Bottom Line

The nationwide injunction debate may seem like an esoteric dispute about the law of civil procedure, but it is much more significant than that. Instead, it is a dispute about the fundamental power of federal courts to review the President's actions. If a given court can decide that a certain policy injures one plaintiff, that court may also be able to stop the President from taking that action altogether, at least in theory.

Both sides of the debate have valid arguments. A federal court that rules in favor of a single plaintiff may not be able to issue a remedy that fully addresses the plaintiff's concerns. Also, a district court may not be the best place for judges to decide questions of national policy, no matter how carefully the court examines the details of the plaintiff's claim. On the other hand, a federal court may have no way to stop an unlawful policy unless the court issues a remedy that stops the policy everywhere at once. Finally, the Supreme Court's new deference to other branches of government may create unwise results in certain situations by removing judicial review altogether.

Each side of the debate contains a fundamentally fair concern, and the difficulty of the injunction debate lies in attempting to balance those concerns.

1. Trump v. CASA, Inc., 606 U.S. 748, 762-79 (2025). The Supreme Court held that the Judiciary Act of 1789 does not authorize federal courts to issue universal injunctions beyond the relief necessary to provide complete relief to plaintiffs and discussed the role of class actions as a mechanism for broader relief.

2. See Samuel L. Bray, Multiple Chancellors: Reforming the National Injunction, 131 Harv. L. Rev. 417, 430-44 (2017).

3. Id. at 457-76.

4. U.S. Const. art. III, § 2, cl. 1.

5. Portia Pedro & Adam Steinman, Aggregation and the "Universal" Injunction, 139 Harv. L. Rev. 1791 (2026). The authors examine universal injunctions as an aggregation problem and argue that class actions can provide an alternative procedural route to broad relief.

6. Fed. R. Civ. P. 23.

7. Administrative Office of the United States Courts, Judicial Facts and Figures, reporting the number of authorized federal district judgeships.