Supreme Court Substantially Limits Universal Injunctions (Trump v. CASA): Implications for Litigation Against the Government

On June 27, 2025, the U.S. Supreme Court issued its long-anticipated decision in Trump v. CASA, Inc., sharply curtailing the ability of federal courts to issue so-called “universal” or “nationwide” injunctions. The 6–3 majority, led by Justice Amy Coney Barrett, held that federal courts lack statutory authority under the Judiciary Act of 1789 to enjoin executive branch policies as to nonparties. Preliminary and permanent injunctions may be issued only to the extent necessary and appropriate to provide “complete relief” to the plaintiffs before the court.

The Court’s decision is likely to recalibrate constitutional and administrative litigation strategies across sectors — particularly in cases challenging executive orders or regulatory policy shifts — by reinforcing the necessity for courts to issue individualized relief. The discussion below explains the Court’s statutory holding and its rejection of universal injunctions, highlights key underlying differences among the Justices — particularly around the scope of Administrative Procedure Act (APA) remedies — and outlines the practical implications for clients. These include potentially greater fragmentation in regulatory enforcement; reduced ability to rely on others’ litigation victories; increased importance of class actions, associational standing, and carefully structured state or organizational suits in securing broad-based relief; and a renewed focus on state court forums as a potential avenue for broader relief in cases against state defendants.

I. Background: Executive Order No. 14160 and the CASA Litigation

The CASA litigation arose from Executive Order 14160, which sought to redefine the scope of birthright citizenship under the 14th Amendment. The order declared that individuals born in the U.S. to mothers who were either unlawfully present or temporarily in the country, and whose fathers were neither citizens nor lawful permanent residents, were not “subject to the jurisdiction” of the United States and thus not entitled to citizenship.

Three federal district courts enjoined the order on a nationwide basis. The government sought partial stays, arguing that universal injunctions exceeded the courts’ equitable authority. Notably, the Supreme Court did not reach the merits of the constitutional challenge to the executive order itself, focusing instead on the scope of equitable relief available to federal courts.

II. The Court’s Holding: “Universal Injunctions” Exceed Courts’ Statutory Authority

Justice Barrett, writing for the majority, held that federal courts lack the authority to issue universal injunctions under the Judiciary Act of 1789. That statute, the Court emphasized, authorizes only equitable remedies traditionally available in the English Court of Chancery at the time of the founding. Because English equity practice recognized only party-specific remedies, the Court concluded that nationwide injunctions lack a statutory basis and are impermissible unless necessary and appropriate to fully redress a plaintiff’s injury.

The majority acknowledged that a broader injunction might be appropriate where narrower relief would be unworkable — such as in cases involving public nuisances, where the only appropriate injunction might be an order to stop the nuisance altogether — but the burden remains on the plaintiff to justify the scope of relief. Moreover, even where such broader relief is appropriate, only the named plaintiffs have the ability to enforce noncompliance. In any event, courts must tailor the remedy to avoid exceeding what is “necessary” to redress harm to the named parties, taking into account both the scope of the plaintiff’s injury and the burden the relief may impose on the defendant.

III. Underlying Disagreement About the APA and Article III

Because the majority rested its holding on statutory grounds, the decision left unresolved questions surrounding the scope of the APA’s “set aside” remedy and Article III. Under 5 U.S.C. § 706(2), courts reviewing agency action “shall … hold unlawful and set aside” rules found to be contrary to law. But whether that language authorizes courts to vacate a rule with effects beyond the parties before the court — or whether such vacatur exceeds Article III limits on judicial power — remains an open question.

This issue has already produced a split among the Justices, as previewed in recent concurrences. In United States v. Texas, Justice Neil Gorsuch (joined by Justices Clarence Thomas and Barrett) suggested that universal vacatur under the APA may be incompatible with traditional equitable principles and Article III. In contrast, in his recent concurrence in Corner Post, Inc. v. Board of Governors of the Federal Reserve System, Justice Brett Kavanaugh has defended broad vacatur as an integral feature of APA review. Accordingly, the Court’s choice in Trump v. CASA to rest its holding on statutory grounds, rather than constitutional ones, may reflect the absence of a consensus on the Article III question and on the scope of appropriate relief under the APA.

IV. Broader Doctrinal and Practical Implications

A. Effects on Uniformity and Review

The Court’s reasoning suggests that federal legal rules may now vary depending on where litigation is brought and who the named plaintiffs are. Despite Justice Kavanaugh’s assurances in his concurrence that the Court will continue to preserve national legal uniformity through its rulings in petitions for emergency relief, the ruling will all but inevitably disincentivize the government from seeking appeals or certiorari following losses that apply only to a small set of plaintiffs. Moreover, as Justice Sonia Sotomayor noted in her dissent, even Supreme Court rulings on injunctions may not bind the Executive as to nonparties, raising further questions about how — and when — legal questions will reach final resolution.

B. Future of Relief Against Government Action

Even when a rule is “set aside” under the APA, Trump v. CASA’s restrictions on injunctive enforcement beyond the parties leave open important questions about practical effect and compliance. Unlike an injunction, a vacatur order under 5 U.S.C. § 706(2) does not itself provide a direct enforcement mechanism such as contempt. As a result, it is conceivable that an agency may respond to an adverse ruling not by abandoning the vacated policy but by reissuing it through adjudications, enforcement actions, or informal guidance — tactics that are not clearly foreclosed by a vacatur order alone. Challenging those follow-on actions would typically require plaintiffs to initiate new litigation rather than rely on the original decision for enforcement. This dynamic may place additional pressure on regulated parties to litigate and may reduce the deterrent effect of APA challenges, especially in the absence of accompanying injunctive relief.

Relatedly, the APA’s “set aside” provision does not apply to the President, because the President is not an “agency” covered by the APA. This means that courts cannot “set aside” executive orders directly, only the implementing actions of subordinate agencies. This limitation, coupled with Trump v. CASA’s rejection of universal injunctions, may sharply restrict relief available against presidential directives unless class relief or associational standing is available.

V. Key Open Questions

State Standing. While Trump v. CASA left open the precise contours of equitable relief available to states, its discussion suggests skepticism toward state-led litigation that seeks de facto nationwide injunctions. The decision may presage a narrower view of state standing in future cases.

Associational Standing. Lawsuits brought by trade associations or membership organizations may now become more central to efforts to secure broader injunctive relief, especially in regulatory cases. However, the Court’s recent standing decisions — and Justice Thomas’s separate writing in Alliance for Hippocratic Medicine — may presage heightened scrutiny of associational standing. At a minimum, organizations will need to demonstrate not only a concrete injury to their members but also the ability to identify those members and show that at least one has standing to sue in their own right.

Class Action Strategy. In light of Trump v. CASA’s limitations on party-specific relief, clients seeking uniform protection against federal policies may need to consider proactive engagement with class litigation. Bringing or joining a class action — particularly under Rule 23(b)(2) — may be the most viable path to securing relief that applies beyond a single plaintiff. Courts may respond to Trump v. CASA by becoming more receptive to provisional class certification, expedited briefing schedules, or other mechanisms to ensure that class-based challenges are timely and effective.

Litigation Against State Defendants. The holding of Trump v. CASA — that federal court injunctions must be limited to what is necessary to redress the plaintiff’s own injury — is equally applicable in federal court suits against state governments. Just as there may be pressure on federal agencies to continue enforcing policies against nonparties notwithstanding adverse plaintiff-specific injunctions, those same pressures may be felt by states where they are defendants. In response, litigants may increasingly seek statewide or universal injunctions in state courts, which are not directly affected by the holding.

VI. Takeaways for Clients

No Piggybacking. Clients should not assume that a favorable ruling obtained by another party will automatically extend to them. Indeed, the opposite is more likely to be true, because under Trump v. CASA, an injunction binds only the parties before the court. Even where a court rules that a federal policy is unlawful, the government may continue to enforce that policy against nonparties unless and until they obtain their own relief. As a result, clients seeking to preserve their legal rights or prevent enforcement actions may need to initiate independent litigation rather than rely on precedents won by others.

Watch for Class Actions. Clients should actively monitor pending class actions that may encompass their interests, particularly in regulatory or APA litigation. If certified, class actions offer a path to uniform protection and preclusive effect — so long as due process requirements, such as adequate notice and representation, are met. Participating as a class member can preserve rights without the burden of separate litigation, but clients should be prepared to act quickly to opt in (or out) where required.

Consider Organizational Membership. In the absence of universal injunctions, associational standing may become a key tool for securing broader relief. Clients may benefit from participating in well-structured trade associations or advocacy groups capable of challenging agency actions on behalf of their members. While recent case law suggests courts may scrutinize associational standing more closely, such groups can still serve as effective vehicles for coordinated legal strategy and targeted injunctive relief.

Examine State Court Litigation Options. In light of Trump v. CASA, clients should assess whether state courts may offer more favorable venues for broad injunctive relief, especially in disputes with state governments. While federal courts are now bound to limit equitable remedies to the parties before them, state courts are not necessarily subject to the same constraints and may retain authority to issue statewide injunctions, including in cases asserting federal claims.

Expect Fragmentation. Companies with operations spanning multiple jurisdictions should prepare for a more fractured regulatory landscape. With injunctions confined to individual plaintiffs or class members, legal obligations may vary by venue or litigation posture. This could lead to compliance asymmetries across regions and greater uncertainty around enforcement. Clients should account for this risk in operational planning, particularly in industries subject to dynamic federal regulatory regimes.

Sidley’s appellate and regulatory litigation teams are actively monitoring related developments, including the Court’s pending APA decisions and emerging class action strategies in public law litigation. Please reach out to discuss how this decision may affect your ongoing or anticipated regulatory challenges.