Universal injunctions after the Supreme Court ruling in Trump v. CASA, Inc. are, for most practical purposes, gone. On June 27, 2025, a 6–3 majority held that these orders “likely exceed the equitable authority that Congress has granted to federal courts,” meaning a single district judge can no longer freeze a federal law, regulation, or executive policy against everyone in the country.1Supreme Court of the United States. Trump v. CASA, Inc. (2025) Relief now generally runs only to the plaintiffs who filed the case. But the Court left three alternative routes open, and the fight over how far those routes extend is already underway in the lower courts.
What the Ruling Actually Held
The case arose from challenges to an executive order on birthright citizenship. Multiple district courts had entered injunctions barring enforcement against anyone in the country, and the government asked the Supreme Court to stay those orders to the extent they reached beyond the actual plaintiffs.
Writing for the majority, Justice Barrett traced federal courts’ equity powers to the Judiciary Act of 1789 and concluded those powers are “confined within the broad boundaries of traditional equitable relief” as it existed at the country’s founding. Courts of equity historically did not issue orders protecting non-parties, so the majority found no basis for universal relief today. Under this framework, district courts using equitable authority under the Judiciary Act may now award “only plaintiff-specific relief.”1Supreme Court of the United States. Trump v. CASA, Inc. (2025)
The Court reaffirmed a principle from Califano v. Yamasaki (1979): injunctive relief “should be no more burdensome to the defendant than necessary to provide complete relief to the plaintiffs.”2Justia US Supreme Court. Califano v. Yamasaki, 442 U.S. 682 (1979) The crucial clarification was that “complete relief” does not mean “universal relief.” A court can fully protect a plaintiff without also shielding every other affected person in the country.
Justice Sotomayor’s dissent, joined by two other justices, warned that the ruling “kneecaps the Judiciary’s authority to stop the Executive from enforcing even the most unconstitutional policies.” Justice Jackson, writing separately, emphasized that a federal court’s power to order the executive branch to follow the law is “particularly vital” when the law at issue is the Constitution itself. Justice Thomas, joined by Justice Gorsuch, concurred to argue the case against universal injunctions was even stronger than the majority acknowledged.
The Three Paths Still Available
The majority explicitly preserved three alternatives for plaintiffs who need broad relief.
First, party-specific preliminary injunctions remain untouched. A plaintiff with standing can still obtain an order blocking enforcement of a policy against that particular plaintiff. If the plaintiff is a state, for example, the injunction may need to extend fairly far simply to give the state full protection.
Second, the Court flagged class actions under Federal Rule of Civil Procedure 23(b)(2). Plaintiffs “may sometimes seek to proceed by class action…and ask a court to award preliminary classwide relief that may, for example, be statewide, regionwide, or even nationwide.”1Supreme Court of the United States. Trump v. CASA, Inc. (2025)
Third, and probably most consequential, the opinion stated: “Nothing we say today resolves the distinct question whether the Administrative Procedure Act authorizes federal courts to vacate federal agency action.” That sentence is the opening through which much of the pre-CASA litigation landscape may flow back in.
APA Vacatur: The Unresolved Question
The Administrative Procedure Act, at 5 U.S.C. § 706(2), tells a reviewing court to “hold unlawful and set aside” agency action that is arbitrary, capricious, contrary to law, or adopted without required procedures.3Office of the Law Revision Counsel. 5 USC 706 The phrase “set aside” is doing enormous work.
Courts and scholars favoring broad relief read “set aside” as authority to vacate the rule itself, stripping it of legal force as to everyone. On this view, vacatur operates on the regulation, not on the defendant’s behavior. An injunction tells the government to stop enforcing a rule against named plaintiffs. Vacatur tells the government the rule no longer exists. The practical effect can match a universal injunction while using an entirely different legal mechanism.4Yale Journal on Regulation. Vacatur of Rules Under the Administrative Procedure Act
Critics counter that § 706 is a standard-of-review provision telling courts how to evaluate agency action, not a remedial provision telling them what to do about it. On that reading, “set aside” does not independently authorize universal remedies.5Yale Journal on Regulation. Section 706 of the Administrative Procedure Act Does Not Call for Universal Injunctions or Other Universal Remedies Supporters of vacatur respond that the language is “consistent with the legislative background of the APA” and that wholesale removal of flawed rules serves an essential function in controlling agency discretion.6Notre Dame Law Review. Vacatur, Nationwide Injunctions, and the Evolving APA
Because the Supreme Court deliberately sidestepped this question, it is now the central battleground. One important boundary: APA vacatur applies only to final agency action governed by the APA, so challenges to statutes or to executive orders that do not qualify as agency action cannot reach for this remedy. For regulations themselves, the vacatur question will likely return to the Supreme Court within the next few terms.
Class Actions as the Procedural Workaround
With universal injunctions curtailed, Rule 23(b)(2) class actions have gained new importance. A certified class action can provide injunctive relief to every class member, potentially spanning the entire country, and the CASA majority explicitly identified this as a viable route.
Certification is not easy. Plaintiffs must satisfy stringent requirements: the class must be so numerous that individual lawsuits are impractical, common legal questions must predominate, the named plaintiffs’ claims must be typical of the class, and the representatives must adequately protect the class’s interests. Supreme Court decisions in recent decades have made certification harder, not easier.7Judicature. One for All: Are Nationwide Injunctions Legal?
Critics of universal injunctions used to argue they functioned as an end-run around these procedural safeguards. Proponents responded that when people face imminent, irreparable harm but cannot quickly file individual cases or wait for class certification, a universal injunction was sometimes the only realistic protection. After CASA, plaintiffs challenging executive action will increasingly need to invest the time and resources to pursue certification, which can take months. That delay may leave large groups unprotected during the process.
The Emergency Docket’s New Role
Justice Kavanaugh’s concurrence addressed the practical fallout. Without universal injunctions, major federal policies could apply in some states but not others for years while litigation plays out. He argued that the Supreme Court itself should resolve this patchwork through its emergency docket, calling it the institution best positioned to provide “nationally uniform” answers about whether new statutes and executive actions remain enforceable during litigation.1Supreme Court of the United States. Trump v. CASA, Inc. (2025)
Some commentators have read this as an invitation for both sides to use the emergency docket far more aggressively. Rather than district judges freezing policy nationwide, the Supreme Court would decide, case by case, whether a challenged executive order or statute remains enforceable while litigation proceeds. That concentrates significant power at the top of the federal judiciary. Whether it proves sustainable is an open question.
To obtain an emergency stay, the government must make a “strong showing” of likely success on the merits and demonstrate likely irreparable harm without a stay. The Court also weighs the balance of equities and relative harms to the parties. In CASA itself, the Court found that when a universal injunction blocks the government from enforcing policy against non-parties, the intrusion on a coordinate branch is sufficient to justify interim relief.
How Lower Courts Are Testing the Line
The CASA opinion did not articulate a clear test for when relief to non-parties remains “necessary to provide complete relief” to the plaintiffs. That ambiguity has turned into a live litigation front.
In cases involving state plaintiffs, religious freedom claims, and grant terminations, several courts have found that non-party injunctions remained necessary to give the actual plaintiffs full relief.8Harvard Law Review. CASA’s Complete Relief Paradox A state suing over a federal regulation, for example, may argue that enforcing the rule against anyone within its borders injures the state in ways that only a broader order can address. How aggressively lower courts can stretch “complete relief” before being reversed is still being worked out.
Different circuits can also still reach opposite conclusions about the same regulation, creating splits that only the Supreme Court can resolve. The difference from the pre-CASA world is that patchwork now runs along party lines and circuit lines rather than being frozen by whichever district judge ruled first.
What the Ruling Did Not Change
Several features of the preliminary injunction landscape are the same as they were before. The four-factor test from Winter v. Natural Resources Defense Council, Inc. — likelihood of success on the merits, irreparable harm, balance of equities, and public interest — still governs whether any preliminary relief issues at all.9Justia US Supreme Court. Winter v. Natural Resources Defense Council, Inc., 555 U.S. 7 (2008) The ruling is about scope, not about the threshold for relief.
The ruling also does not touch state court injunctions, injunctions against private defendants, or final judgments on the merits after a full trial. Its direct focus is on federal district courts exercising equitable authority under the Judiciary Act in cases against the federal government.
What This Means If You Are Challenging Federal Policy
For a plaintiff weighing a challenge to a federal law, regulation, or executive order, the practical consequences are concrete.
If you need protection only for yourself or your organization, nothing has changed in a meaningful way. File the case, seek a preliminary injunction, and ask the court to block enforcement against you. The scope question that dominated pre-CASA litigation does not arise.
If you need protection for a broader group, you have real work to do. A class action under Rule 23(b)(2) is now the primary mechanism, and the certification process adds months. If the policy you are challenging is a final agency action, APA vacatur may offer a faster route to broader relief, but you should expect vigorous arguments about whether § 706 authorizes that remedy and should prepare the case accordingly. If the challenged policy is a statute or an executive order that does not qualify as agency action, APA vacatur is not available.
If the harm is immediate and widespread and you cannot wait for class certification, the realistic path to a uniform national answer now runs through the Supreme Court’s emergency docket rather than through a single district judge. That changes how briefs get written, how records get built, and how fast a case needs to move. The judge who hears your case first still matters, but that judge can no longer stop the policy for the whole country, and planning the litigation on the assumption otherwise is a mistake the ruling has foreclosed.