Challenging Federal Government Actions After Trump v. CASA: New Limits and Open Pathways

The Supreme Court’s decision in Trump v. CASA, Inc. marks a major shift in how federal courts may police executive action. In the Court’s June 27, 2025 decision, a 6-3 majority held that so-called “universal” or nationwide injunctions — orders barring enforcement of a federal law or policy against all persons, not just the parties before the court — exceed the equitable authority that Congress granted to federal courts. But even as it restricted universal injunctions, the Court in CASA left open other potential bases for broad relief. The decision offers important lessons for entities affected by government action to protect their interests.

The Supreme Court’s CASA Decision

CASA arose from President Trump’s executive order seeking to restrict birthright citizenship under the Fourteenth Amendment. Three federal district courts issued injunctions blocking the president’s order nationwide. The Trump administration sought partial stays of those orders in the Supreme Court — focusing its attack not on the lower courts’ constitutional rulings, but rather on the nationwide scope of the injunctions.

The Supreme Court held that the universal injunctions were improper. Justice Barrett’s majority opinion rested on the Judiciary Act of 1789 — the statute that authorizes federal courts to issue remedies like injunctions. The Court held that the Judiciary Act authorizes only those remedies traditionally available in English courts at the time the United States was founded. The Court viewed that historical tradition as largely foreclosing universal injunctions. The Court acknowledged, however, that there may be situations where granting a broad injunction is necessary to provide the plaintiff “complete relief” in the case.

Open Avenues and Open Questions

What remains of universal relief after CASA? Three avenues are most promising, but each carries uncertainty.

1. APA Relief. CASA explicitly declined to address the “distinct question” of relief in cases brought under the Administrative Procedure Act (APA). The APA allows challenges to federal agency actions and instructs courts to “hold unlawful and set aside” impermissible actions.

Historically, courts have understood this language to authorize universal vacatur — that is, invalidation beyond the particular parties. Even before CASA, however, the government argued that the APA must be read in harmony with traditional equity limits and thus does not permit universal vacatur. Justices Gorsuch, Thomas, and Barrett have signaled support for that restrictive view; Justice Kavanaugh has taken the opposite position (and reiterated that position in CASA), and Chief Justice Roberts has shown skepticism during oral arguments (calling the no-universal-vacatur position “radical” and quipping that judges on the D.C. Circuit vacate rules “five times before breakfast”).

Yet two issues complicate APA remedies. Most critically, there are major unanswered questions about preliminary relief under the APA. CASA’s restrictions apply to all injunctions, including preliminary injunctions — ones granted early in the case to prevent irreparable harm to the parties. The APA authorizes courts to issue similar temporary relief in the form of a stay. Courts generally apply the same standard to determine whether a temporary stay is warranted under the APA that they apply in evaluating the propriety of a preliminary injunction. That parity could suggest (as one court recently concluded) that CASA’s limitations apply equally to APA stays. And yet there are strong arguments rooted in the APA’s text, structure, and history that the law authorizes universal stays.

The APA remedy has another key limitation: It applies only to “agency” action. The Supreme Court has held that the president is not an agency. Many presidential policies must be implemented through agency actions, which are subject to challenge under the APA. But some presidential orders — like the birthright citizenship order — are self-executing and arguably not subject to APA review (although even this issue is unsettled). CASA’s limits will be most consequential for these sorts of presidential actions with immediate, self-executing consequences.

2. Class Actions. CASA leaves intact broad injunctions protecting members of a properly certified class under Rule 23(b)(2) of the Federal Rules of Civil Procedure. In CASA, Justice Kavanaugh’s concurring opinion and Justice Sotomayor’s dissenting opinion both highlighted this procedural pathway.

Litigants have already used Rule 23(b)(2) successfully in the birthright citizenship litigation, starting immediately after the Supreme Court’s decision. A Maryland district court granted class certification under Rule 23(b)(2) and issued a nationwide injunction covering all children who would otherwise obtain citizenship. A New Hampshire district court followed a similar path.

These moves underscore how class actions may be increasingly important tools for challenging government action. But they also reflect limits on class remedies. Class actions must meet specific criteria, including commonality and typicality — basically, that the class members’ circumstances are sufficiently alike for class-wide adjudication. In the Maryland case, the court certified a class for children but denied certification for parents in their individual capacities, finding their fears about their children’s citizenship to be too individualized. For government actions imposing varied burdens across regulated entities, these hurdles may be difficult to overcome.

3. Organizations and States. Several of the plaintiffs in CASA were large membership organizations suing on behalf of many members. The Court did not question the ability of those organizations to secure injunctions covering their members, so long as the traditional requirements of “associational standing” are met. But there has been renewed interest — especially from Justice Thomas — in restricting the availability of organizational standing. The government, too, has contested broad injunctions for organizations post-CASA (although its efforts were recently rejected in the birthright citizenship context).

CASA also leaves unsettled the availability of injunctions for states as plaintiffs. Such injunctions could extend broadly if a state can credibly claim that a universal injunction is necessary to fully redress its injuries. Several plaintiffs in CASA were states, and the states claimed that, given cross-border flows of children and their parents, it would be impossible to fully redress their financial injuries and administrative burdens without injunctions extending beyond the state’s borders. While the Court in CASA expressed some skepticism that this rationale could justify a universal injunction, it did not definitely resolve the question, and courts on remand upheld universal injunctions for the states on this theory.

4. CASA’s “Complete Relief” Caveat. Finally, CASA acknowledged that universal injunctions may still be warranted when necessary to give plaintiffs complete relief. The Court cited examples — a nuisance injunction requiring a defendant to “turn down her music” or an order blocking a racially gerrymandered map — where full relief to one plaintiff inevitably benefits others. Plaintiffs who can analogize their situation to those examples may still obtain broad injunctions.

That said, the practical benefits of this “complete relief” carveout may be limited. The Court emphasized that even when such an injunction extends more broadly, “only the plaintiff can enforce the judgment against the defendant.” Non-parties who are nominally protected by the injunction cannot necessarily protect their interests if the government does not abide.

Takeaways

CASA may not mark the end of universal relief, but it unquestionably changes the landscape for parties affected by government action. Affected organizations and individuals should consider several steps to ensure their interests are best protected:

• Closely Monitor Litigation. Before CASA, affected parties generally could expect that any litigation challenging a new federal policy — if ultimately successful — would benefit them even if they were not plaintiffs. CASA complicates that calculus. By default, injunctions blocking federal action leave the government free to enforce that action against anyone who was not a plaintiff in the case — unless and until the party secures an injunction itself. Tracking litigation involving new government actions is more important than ever, including because after CASA joins that litigation (or files a new case), it may be necessary to protect the entity’s interests.
• Prepare for Patchwork Remedies. Compliance with federal regulation will inevitably be more complicated in a post-CASA world. As noted, courts have continued to read the APA as authorizing universal vacatur. But CASA may limit the preliminary relief awarded in any case to the specific parties challenging the policy. That can mean months, if not years, where the policy is enforceable as to some but not all parties, or in some but not all geographic areas.
• Leverage Organizations and States. As noted, CASA did not foreclose broad injunctions protecting all members of an organization with standing to challenge a particular federal policy. Joining organizations that are ready and willing to challenge government action is likely to be an increasingly important strategy for entities subject to federal action. Relatedly, partnership or collaboration with states capable of challenging federal policy could be mutually beneficial.
• Carefully Consider Causes of Action and Remedies. The APA’s potential for universal vacatur makes the APA a more attractive procedural vehicle than ever before. Any challenge to a new presidential policy should consider the availability of agency defendants so as to unlock use of the APA, and should be careful to preserve all arguments that the APA authorizes regarding broad relief notwithstanding CASA.
• Keep an Eye on Class Actions. In the wake of CASA, Rule 23(b)(2) class actions are likely to become a more popular vehicle for securing broad, uniform relief against federal policies. If that trend continues, individuals and organizations affected by a government action could benefit from class litigation — or may find themselves swept into certified classes, even if they have not personally chosen to litigate. Potential class members should pay attention to new filings in their area of interest and consider whether to participate or coordinate with class counsel to protect their specific interests. For clients who might otherwise have relied on a nationwide injunction to safeguard their rights, proactive engagement with class litigation may be an essential part of any effective strategy.

Arnold & Porter will continue to monitor developments affecting the scope of relief in challenges to federal government actions. Our team has extensive experience in administrative and regulatory litigation, including challenges to presidential and agency actions. If you have questions, please reach out to one of the authors of this post or your regular Arnold & Porter contact.

Bonnie Devany contributed to this Blog post. Ms. Devany is admitted only in Texas; practicing law in the Washington, D.C.  during the pendency of her application for admission to the D.C. Bar and under the supervision of lawyers of the firm who are members in good standing of the D.C. Bar.

© Arnold & Porter Kaye Scholer LLP 2025 All Rights Reserved. This Blog post is intended to be a general summary of the law and does not constitute legal advice. You should consult with counsel to determine applicable legal requirements in a specific fact situation.