Justice Sotomayor’s principal dissent in Trump v. CASA, Inc. is a robust defense of a fundamentally different conception of judicial equity—one that views it not as a static collection of remedies frozen in 1789, but as a dynamic and adaptive power essential for realizing constitutional guarantees in the modern era. Her critique targets both the majority’s historical methodology and the severe practical consequences of its ruling, arguing that the rigid formalism adopted by the Court paralyzes the judiciary’s ability to respond to systemic unlawful government action, particularly when that action is “patently unconstitutional.”
The central jurisprudential disagreement is with the majority’s interpretation of the Judiciary Act of 1789 and its application of the Grupo Mexicano standard. Sotomayor argues that the majority “fundamentally misunderstands the nature of equity” by insisting on a direct historical analogue for every modern remedy. In her view, the Judiciary Act codified equity itself—the inherent power and discretion to “do complete justice” and adapt to unforeseen exigencies—not merely the specific writs available in the English Court of Chancery. Equity, by its very definition, was designed to evolve where rigid legal forms proved inadequate. By treating equity as a “closed system,” the majority betrays its essential characteristic.
Sotomayor challenges the majority on its own historical terms, arguing that the universal injunction does possess sufficient historical analogues when viewed functionally rather than formalistically. She reframes the “bill of peace” and early American taxpayer suits as evidence of equity’s long-standing capacity to provide broad relief to non-parties to prevent a multiplicity of suits and offer complete justice to a community. Where the majority emphasizes the procedural differences between the bill of peace and the universal injunction (such as the size of the group and the binding effect on absent parties), Sotomayor focuses on the shared underlying principle: utilizing a single suit to provide broad relief against a generally applicable harm.
Moreover, the dissent implicitly questions the appropriateness of the 1789 anchor point, particularly in the context of modern American constitutional law. She points out that remedies like the injunction against government officials authorized by Ex Parte Young (1908) evolved in the United States despite having no analogue in the English Chancery, which could not enjoin the Crown. This evolution demonstrates that American equity necessarily adapted to the demands of a system based on judicial review and constitutional constraints on government power. The majority’s rigid historical test, she suggests, is inconsistent with the recognized legitimacy of the foundational tools of modern public-law litigation.
Sotomayor also points to the Court’s own history of functionally universal relief in landmark cases like Pierce v. Society of Sisters (1925) and West Virginia Board of Education v. Barnette (1943). While these decisions may not have explicitly analyzed the scope of the remedy, they enjoined the enforcement of unconstitutional laws in a manner that protected entire populations. For Sotomayor, this history demonstrates that constitutional violations affecting broad populations have traditionally justified broad remedial responses, regardless of 18th-century limitations.
The dissent is acutely aware of the practical implications of the majority’s ruling, particularly in the context of the specific dispute. Sotomayor strategically foregrounds the merits, emphasizing the “patent unlawfulness” of the Executive Order on birthright citizenship. This framing is crucial: it suggests that the clarity of the constitutional violation should inform the scope of the remedy. When the government acts in blatant defiance of settled law—here, the Fourteenth Amendment and United States v. Wong Kim Ark (1898)—the need for a swift, comprehensive judicial response is at its zenith.
She accuses the government of “gamesmanship” by strategically challenging only the remedy while avoiding a defense of the indefensible merits. The majority, in her view, is “complicit” in this strategy, using a case involving a clear constitutional violation to radically reshape remedial law while allowing irreparable harm to occur.
Ultimately, Justice Sotomayor’s dissent is a defense of a purposive, adaptive judiciary capable of checking executive overreach in the modern state. Her vision of equity is deeply intertwined with the judiciary’s role in constitutional governance. By prioritizing historical formalism over functional necessity, she argues, the majority weakens the courts' ability to protect constitutional rights effectively, rendering those guarantees “meaningful in name only” for those unable to bring suit themselves. The conspicuous omission of the traditional “respectfully” signals the depth of this jurisprudential divide and the gravity of the stakes involved.