A nationwide injunction is a federal court order that blocks the government from enforcing a law or policy against anyone in the country, not just the people who filed the lawsuit. For most of the past decade, a single federal district judge could freeze a federal policy everywhere at once using this tool. That is no longer the default. In June 2025, the Supreme Court ruled in Trump v. CASA, Inc. that federal courts generally lack the authority to issue universal injunctions and that injunctive relief should extend only to the actual plaintiffs in a case.1Justia. Trump v. CASA, Inc., 606 U.S. ___ (2025) Broad relief against federal action is still possible, but the pathways are narrower and more procedurally demanding than they were before.
What CASA Changed
Trump v. CASA, Inc. was decided on June 27, 2025. It grew out of challenges to an executive order on birthright citizenship, where three district courts had each issued injunctions blocking enforcement nationwide. The government asked the Supreme Court for partial stays, and the Court used the occasion to address universal injunctions directly.
The holding was blunt: federal courts lack authority to issue universal injunctions. The Court grounded its reasoning in the Judiciary Act of 1789, which gave federal courts jurisdiction over suits “in equity.” Because the statute incorporates only those equitable remedies that were traditionally available at the founding, and because nothing resembling a universal injunction existed at the founding or for more than a century afterward, the Court concluded that district courts may award only plaintiff-specific relief.1Justia. Trump v. CASA, Inc., 606 U.S. ___ (2025)
The Court did leave some room. An injunction that provides complete relief to the actual plaintiffs may, as a practical matter, benefit people who are not parties. The Court acknowledged this possibility but stressed that “complete relief is not a guarantee — it is the maximum a court can provide,” and that the broader and deeper the requested remedy, the stronger the plaintiff’s case needs to be.1Justia. Trump v. CASA, Inc., 606 U.S. ___ (2025) The ruling also does not disturb Rule 23 class actions, so plaintiffs can still seek certification of a nationwide class if they satisfy the procedural requirements.
The Dissent
The decision was sharply contested. Justice Sotomayor’s dissent argued that adaptability has always been a hallmark of equity and that stripping federal courts of universal relief “kneecaps the Judiciary’s authority to stop the Executive from enforcing even the most unconstitutional policies.” Justice Jackson wrote that requiring every affected person to individually find a lawyer and file a case before their rights are protected amounts to “perverse burden shifting” that “cannot coexist with the rule of law.”
What Still Produces Broad Relief
The end of universal injunctions did not close every route to nationwide impact. Three pathways survived CASA, though each has limits.
Vacatur Under the APA
The Administrative Procedure Act, at 5 U.S.C. § 706, instructs courts to “hold unlawful and set aside” agency actions that are arbitrary, an abuse of discretion, or contrary to constitutional rights.2Office of the Law Revision Counsel. 5 USC 706 – Scope of Review The traditional reading is that when a court “sets aside” an agency rule, the rule is vacated — nullified and drained of legal effect for everyone, not just the parties before the court. Vacatur operates on the rule itself rather than ordering officials to stop enforcing it. Justice Kavanaugh’s concurrence in CASA acknowledged that plaintiffs in APA cases may still ask a court to “set aside” a new agency rule, suggesting this pathway is distinct from the universal injunction the majority struck down.
The future of vacatur is unsettled. Justice Gorsuch argued in United States v. Texas that “set aside” merely instructs courts to disregard an unlawful rule when deciding the specific case before them, not to erase it entirely.3Justia. United States v. Texas, 599 U.S. 670 (2023) With universal injunctions now disfavored, courts and litigants are working through whether vacatur accomplishes the same result under a different label.
Certified Class Actions
The CASA majority explicitly preserved Rule 23 class actions as a mechanism for broader relief. If a court certifies a nationwide class under Rule 23(b)(2), it can issue an injunction that protects every class member, potentially millions of people. The catch is that class certification is procedurally demanding. Plaintiffs must satisfy requirements for numerosity, commonality, typicality, and adequate representation. That process takes time, which is exactly what plaintiffs lack when trying to halt government action before it causes widespread harm.
Incidental Benefits of Party-Specific Relief
Even a narrowly drawn injunction can have broad practical effects. If a court orders the government to stop enforcing a policy against a specific plaintiff, that ruling signals how the court views the policy’s legality. The government may then voluntarily pause enforcement against similarly situated people rather than face a wave of individual lawsuits. Justice Thomas acknowledged in his concurrence that certain “indivisible remedies,” such as injunctions against public nuisances, may incidentally benefit nonparties, though he stressed that such cases should be rare.
What It Takes to Get an Injunction
Whether an injunction covers one plaintiff or an entire certified class, the threshold for preliminary relief is the four-factor test from Winter v. Natural Resources Defense Council, Inc.:4Justia. Winter v. Natural Resources Defense Council, Inc., 555 U.S. 7 (2008)
- Likelihood of success on the merits. The plaintiff must show a strong probability that the challenged law or policy is illegal or unconstitutional. Courts do not freeze government operations for claims built on speculation.
- Irreparable harm. The plaintiff must demonstrate that without immediate intervention, they will suffer injuries that money or other post-trial remedies cannot fix. A business that would be forced to shut down permanently, or a person facing deportation under a contested order, may meet this standard.
- Balance of equities. The court weighs the potential damage to the plaintiff against the disruption to the government and affected third parties.
- Public interest. The court considers whether granting the injunction serves or disserves the broader public. When the government is the opposing party, this factor and the balance of equities effectively merge.
All four factors must favor the plaintiff. A strong merits case alone is not enough if the plaintiff cannot show real, imminent harm that outweighs the cost of halting government action.
How the Government Fights an Injunction
When a district court issues a preliminary injunction against the federal government, the appellate machinery kicks in almost immediately. The government’s first move is typically to seek a stay, a pause that lets it keep enforcing the policy while the appeal proceeds.
Federal Rule of Appellate Procedure 8 requires the government to first ask the district court itself for a stay. If the district court refuses or fails to act, the government can then bring the request to the relevant Circuit Court of Appeals.5Legal Information Institute. Federal Rules of Appellate Procedure Rule 8 – Stay or Injunction Pending Appeal The appellate court evaluates the request using the four-factor framework from Nken v. Holder: whether the government has shown a likelihood of success on the merits, whether it would be irreparably harmed without a stay, whether issuing the stay would substantially injure the other parties, and where the public interest lies.6Library of Congress. Nken v. Holder, 556 U.S. 418 (2009)
If the circuit court denies the stay, the government can file an emergency application with the Supreme Court. Under Supreme Court Rule 23, these applications will not be entertained unless the applicant first sought relief from the lower courts.7Legal Information Institute. Supreme Court Rules Rule 23 – Stays These requests land on what practitioners call the shadow docket, where the Court makes consequential rulings without full briefing or oral argument. In politically charged cases, this expedited pathway has become the primary mechanism for resolving injunction disputes, sometimes within days of the original order.
Appellate courts give deference to the district court’s factual findings but review legal conclusions independently. After CASA, one of the most important legal questions on review is whether the injunction’s scope is properly limited to the plaintiffs. An appeals court that finds the injunction sweeps beyond what is necessary for complete relief to the named parties will narrow it.
Why the Court Got Here
CASA did not emerge from nowhere. It capped years of pointed criticism from individual justices. Justice Thomas wrote a concurrence in Trump v. Hawaii (2018) arguing that universal injunctions “appear to be inconsistent with longstanding limits on equitable relief and the power of Article III courts.”8Legal Information Institute. Trump v. Hawaii He contended that for most of American history, judicial power was understood as the power to render judgments in individual cases, not to make federal policy or strike down laws. He also noted that the founding generation viewed equity with suspicion and that courts traditionally provided relief only to parties who demonstrated a specific injury.
Justice Gorsuch picked up the thread in United States v. Texas (2023), challenging the APA’s role as a source of universal relief. He argued that the APA section titled “Scope of review” concerns the court’s decision-making process, not the remedies available after judgment. Reading “set aside” as a command to disregard an unlawful rule during the court’s analysis, rather than as a power to erase the rule for everyone, would keep judicial treatment of agency rules parallel to how courts treat statutes, which courts have never claimed the power to vacate.3Justia. United States v. Texas, 599 U.S. 670 (2023)
Defenders of broad injunctive relief pushed back with historical research suggesting that universal injunctions have deeper roots than critics acknowledged. Some scholars have identified federal court orders reaching beyond the named plaintiffs as far back as 1913, arguing that the practice has a more established lineage than the “recent invention” narrative implies. That debate now plays out in the lower courts as judges work through CASA‘s implications for vacatur, class certification, and the practical scope of party-specific relief.