What Happens in the Lawsuit Stays in the Lawsuit: How the Trump V. CASA Inc. Ruling on Universal Injunctions Upsets the Balance of Powers

A law for all and a ruling for a few, the loss of universal injunctions after Trump V. CASA Inc. earlier this summer signals the arrival of a new era in utilizing universal remedies for unlawful government actions. Trump V. CASA Inc. (2025) is part of a series of lawsuits against President Donald Trump in response to Executive Order 14160 (Protecting the Meaning and Value of American Citizenship). Issued on January 20, the executive order aims to reinterpret the Fourteenth Amendment and eliminate birthright citizenship for those born to parents that are not citizens or permanent lawful residents of the United States. [1] Individuals, states, and immigrant rights organizations such as CASA sued President Trump alleging the unconstitutionality of the order. As the order was to be implemented on February 19, 2025, various plaintiffs filed a motion for a preliminary universal injunction—an order that both applies to all people, notwithstanding their classification as a non-party, and that halts enforcement of the executive order, which is likely to cause harm, while it is under judicial review. 

Multiple courts granted universal injunctions, which the defendant then appealed unsuccessfully at the appellate level. The case then reached the Supreme Court, which examined the case on procedural grounds. The Justices did not examine the merits of the case nor decide on the constitutionality of the executive order. Instead, they focused on whether the courts were allowed to issue the injunctions. In a 6-3 decision, the U.S. Supreme Court decided that universal injunctions are beyond the equitable authority held by federal courts. [2] The court stayed the universal injunctions and remanded the case back to lower courts to determine what narrower remedy can be made. The Supreme Court’s recent decision in Trump V. CASA Inc. overlooks historical precedent and relies on an understanding of equity that will prove burdensome for both parties and non-parties alike. 

In its opinion in Trump V. CASA Inc., the Court searched for a founding-era basis for universal injunctions because of the holding of Grupo Mexicano de Desarrollo, S. A. V. Alliance Bond Fund Inc. (1999). In this case, the Supreme Court held that federal courts do not have the equitable authority to issue a preliminary injunction forcing a defendant from disposing of assets pending a money judgement. The Court reasoned that because such a remedy was not available in the English Court of Chancery during the time period in which the constitution and Judiciary Act of 1789 were enacted, they could not offer such a remedy now. [4] As such, courts today have to examine the practices of the Court of Chancery when determining what is under equitable authority now over two centuries later. 

Due to the evolving nature of society, not many practices from that era align with today’s issues. Nevertheless, an argument can be made for the practice of bills of peace being a precedent for universal relief. An amicus brief issued by legal historians in support of the respondents in Trump V. CASA Inc. explored the legal history of bills of peace. They found that bills of peace granted rights to non-parties in claims where many individuals shared an interest, but it would be impractical to join them all in the suit. [5] Bills of peace provide a historical basis for relief for non-parties with a common interest, much like the aim of universal injunctions. While never explicitly established nor rejected, universal injunctions can find their root in the Court of Chancery’s concepts of equity and efficiency. Therefore, the Supreme Court should not have ruled that universal injunctions lack a historical pedigree on the basis of the equitable authority established by the English Court of Chancery. Additionally, Article III of the U.S. Constitution establishes the judicial power of the United States as “extend to all Cases, in Law and Equity.” [3] This provides a constitutional foundation for courts to exercise power to issue remedies in cases of equity, which include injunctive relief. 

For contemporary purposes, case law also shines a light on the concept of equity in the U.S. judicial system. The language used in Smyth V. Ames (1898) shows that courts of equity can “...determine once for all, and without a multiplicity of suits, matters that affect not simply individuals, but the interests of the entire community,” further supporting the historical concept of non-party relief and universal application of remedies. [6]

The Supreme Court’s decision also neglects a history of the de facto use of universal injunctions, in which even the Court itself has ruled in favor. Pierce V. Society of Sisters (1925) provides an instance in which the Supreme Court affirmed a lower court’s use of a preliminary injunction that prevented the governor and state officials from enforcing a state law on education not just for the plaintiff but for the state of Oregon as a whole. [7] This is similar to Trump V. CASA Inc. in that the injunction provided relief for non-parties also affected by an alleged unconstitutional governmental action. In this case, the Supreme Court did not find merit to challenge the equitable authority of such an injunction despite it posing the same concerning characteristics as the Trump V. CASA Inc. injunctions. 

The Court has issued its own relief to non-parties beyond what’s necessitated for complete relief for plaintiffs, notably in Lewis Publishing Company v. Morgan (1913). Lewis Publishing Company and the Journal of Commerce sued over a provision of the Post Office Appropriation Act (1912) requiring newspapers to supply the names of their editors and shareholders, which they alleged was an attempt to regulate the press, violating the First Amendment. Although the Court ultimately deemed the provision constitutional, it is the procedural history of the case that is relevant to universal injunctions. [8] It’s been noted that the Supreme Court issued a preliminary injunction in Lewis benefiting non-parties by blocking the enforcement of the federal statute against “other newspaper publishers” beyond the plaintiffs of the case. [9] Effectively, the Court willingly granted relief to non-parties notwithstanding that doing so was unnecessary to provide relief to plaintiffs.

The majority opinion in Trump V. CASA Inc. poses the concern of straying away from the “party-specific principles that permeate the Court’s understanding of equity,” principles which find their root in the English Court of Chancery ‘typically’ issuing party-specific remedies. [10] While parties are important to understanding each group's role in a lawsuit and determining the eligibility of bringing a case to court, the court’s decision to limit courts to party-specific remedies neglects the Court’s responsibility to work as a check and balance on the other branches of government. This limitation to only party-specific relief allows the Court to check the power of other branches only in relation to certain individuals, despite determining an overreach affecting many more individuals.

The benefitting non-parties in Trump V. CASA Inc. and any similar lawsuit against unconstitutional governmental action do have Article III standing–otherwise, they would receive no benefit from having the government action enjoined. In other words, non-parties have suffered or will suffer an injury due to the unlawful actions of the government and can be given relief through a judicial decision indicating they are viable as parties to lawsuits. [11] As Justice Jackson explores in her dissenting opinion, the discontinuance of the universal injunction will hurt people that have standing to be part of a party but no means to effectively and efficiently challenge the governmental action in court before irreparable harm is done to them. [12] This does not bode well for the principles of equality of which the United States is built on.

Even with the determination that only party-specific remedies are allowable, universal injunctions may be necessary to avoid further burdening plaintiffs. In her dissenting opinion, Justice Sotomayor provides an example of a baby born following the implementation of Executive Order 14160. She detailed the many opportunities for a mistake to occur while determining parentage, citizenship status of parents and membership for those receiving relief under an organization or a state that has sued. [13] Additionally, if a state were to receive relief in the form of an injunction, many questions will be raised as to how to manage geographically diverse federal law and will prove to be an administrative burden and lead to confusion that risks plaintiffs not being able to receive their awarded relief. A narrower injunction as the Supreme Court is asking of the lower courts for Trump V. CASA Inc. will fail to provide plaintiffs proper relief as they operate under a “patchwork injunction” and the many difficulties and uncertainties that follow that. There must, then, be a recalibration of the balance between party principles and equity principles in order to ensure proper relief for those seeking it.

In the wake of the Court’s decision, those aiming to preserve the rights of all against unconstitutional actions during the interim period of judicial review must look towards other methods of doing so. In the opinion of the court, Justice Barrett declares that class action lawsuits are the modern-day equivalent of bills of peace, establishing class actions as an appropriate method to receive relief for a group of people. [10] Class action lawsuits, authorized under Federal Rules of Civil Procedure Rule 23, are a tool which allows for people who have suffered similar harm to file a singular lawsuit in which representatives represent the interests of the entire class in court. [14] Rule 23 details the four prerequisites for forming a class action, being numerosity, commonality, typicality, and adequacy of representation. Early on in the lawsuit, once a class has met the prerequisites, a judge can certify them, which includes detailing the members, claims and counsel. Once a class has been certified, the class action may continue. Members can be defined using an overarching characteristic that the class shares and is pertinent to the suit. Such a definition will likely lead to absent parties, or members of the class that are not active in the suit. For instance, a class may consist of users of a certain product which the class action aims to prove caused the plaintiffs to suffer harm. Such an encompassing characteristic is likely to bring many people to a suit, not all of whom will be active participants but will be bound to the ruling of the court. 

With respect to being an alternative to universal injunctions, class action lawsuits may provide similar widespread relief if all those affected join the class action and an injunction is ordered. However, this may prove to be burdensome and raises questions about the role of absent parties in class actions. When the question at hand is the constitutionality of an executive order, as was the case in Trump V. CASA Inc., the number of individuals who have suffered potential harm can range up to the entirety of the U.S. population. This may not be an issue if the court allows the “opt-out” method of joining the class, where all potential individuals are a part of the class, unless they explicitly decide not to participate. The “opt-out” method, while commonly used, may not always be a guarantee, especially in the ever-shifting post-Trump V. CASA Inc. legal landscape. The more frequent use of class actions will exacerbate related divisive issues. The repeated use of nationwide classes may provoke a reevaluation of the merit of interest commonality over consent when certifying the members of a class action, pushing forward an “opt-in” structure that will create much smaller and less inclusive classes. 

Moreover, the increased use of class action lawsuits will raise questions about the status of absent class members for various purposes, a topic academics have debated for over five decades. In a note for the Virginia Law Review, Abby Porter examined the two vastly different approaches to including absent class members that Judge Diane Wood dubbed the “joinder” and “representational” models in her 1983 article on the topic. [15] Both works highlight the inconsistencies that apply to class actions and the expectations for absent class members that vary lawsuit to lawsuit. Due to the nature of these proposed nationwide class action lawsuits, a significant portion of the class will be absent and may prove burdensome on the court and members depending on the current acceptable model. Porter provides the example of over three million Peloton subscribers needing to consent to being adjudicated by a magistrate under the joinder model in comparison to just the named class members under the representative model. [15] Similar issues of practicality will arise with the increase in large class actions and nonstandard treatment of absent members. 

Barbara V. Trump (2025), the class action lawsuit filed after the release of the Supreme Court’s ruling in Trump V. CASA Inc. marks the beginning of “nationwide” class actions to achieve far-reaching relief. While the method is proving successful, as the class was certified and granted a preliminary injunction for all people affected by the executive order on July 10th, there are still many issues that will arise as nationwide class actions become the new “universal injunction.” [16] Class action lawsuits are a current solution to the Court’s party-centric relief objective, but there are still likely to be challenges to such an alternative that can halt government action at the singular court level.

Justice Kavanaugh, in his concurring opinion in Trump V. CASA, deems Section 706(2) of the Administrative Procedure Act as a viable alternative path towards receiving the equivalent of a universal injunction. [17] The Administrative Procedure Act (APA), enacted in 1946, governs administrative law and section 706(2) grants courts the ability to “hold unlawful and set aside agency action” also known as vacatur. [18] This being a legal solution for the absence of universal injunctions presumes that the APA grants federal courts the power of universal vacatur, or setting aside the agency action for all. In a footnote in the opinion of the court, Justice Barrett establishes that this is still a question to be resolved, indicating that there may be a future ruling limiting federal courts’ ability to set aside agency action at the nationwide level. [10] Additionally, Section 706(2) does not explicitly grant courts the power to preliminarily set aside agency action and forces the court to hold the agency action unlawful in order to set it aside. [18] Holding that the action is unlawful requires the court to reach a decision, limiting its ability to take preliminary action leaving room for a future interpretation by the Supreme Court eliminating preliminary universal vacatures. In the interim of such rulings, the APA stands as a method to set aside agency regulations established in support of unconstitutional executive orders. 

The Supreme Court’s injunction on universal injunctions marks a decline in the judicial power to uphold the law and restricts the remedies available to protect the public from dangerous governmental actions. As pressure shifts to other legal tools, such as class actions and the APA, to fill the hole of universal injunctions, there will likely be increased scrutiny and questions regarding the power of the federal courts, further disrupting the balance of powers within the U.S. government. 

Edited by Cara Wreen

[1] Exec. Order No. 14,160, 90 Fed. Reg. 8449 (2025).

[2] Trump V. CASA Inc., No.24A884, slip op. at 2 (2025).

[3] U.S. Const. art. III, § 2, cl. 1.

[4] Grupo Mexicano de Desarrollo, S. A. v. Alliance Bond Fund, Inc., 527 U.S. 308 (1999).

[5] Brief for CASA Inc. et al. as Amici Curiae Supporting Respondents, Trump V. CASA Inc., No.24A884, slip op. (2025).

[6] Smyth v. Ames, 169 U.S. 466 (1898).

[7] Pierce v. Society of Sisters, 268 U.S. 510 (1925).

[8] Lewis Publishing Co. v. Morgan, 229 U.S. 288 (1913).

[9] Mila Sohoni, “The Lost History of the ‘Universal’ Injunction,” Harvard Law Review 133, no. 3 (2020): 925.

[10] Trump V. CASA Inc., No.24A884, slip op. at 14 (2025).

[11] Lujan v. Defenders of Wildlife, 504 U.S. 555, 560–61 (1992).

[12] Trump V. CASA Inc., No.24A884, slip op. at 115 (2025).

[13] Ibid, slip op. at 91.

[14] Fed. R. Civ. P. 23.

[15] Abby Porter, “Parties or Not?: The Status of Absent Class Members in Rule 23 Class Actions,” Virginia Law Review 109, no. 3 (2023): 713.

[16] Barbara et al V. Trump et al., No. 1:25-cv-00244, (D.N.H. 2025).

[17] Trump V. CASA Inc., No.24A884, slip op. at 43 (2025).

[18] Administrative Procedure Act, §10, 5 U.S.C. § 706.