What court rulings and legal constraints affected the Biden administration's ability to change Remain in Mexico (MPP) and Title 42 expulsions?
Executive summary
The Biden administration’s efforts to unwind the Trump-era “Remain in Mexico” (MPP) and to end Title 42 expulsions were repeatedly reshaped by a web of federal court rulings, appellate decisions and administrative-law constraints that both limited and later restored executive discretion; key decisions included lower-court injunctions ordering continuation of policies, the Supreme Court’s split interventions, and procedural hurdles under the Administrative Procedure Act (APA) and public‑health rulemaking requirements [1] [2] [3]. These legal moves were driven by competing claims about statutory authority, standing by states to sue, and whether public‑health or immigration law governed the practices — and they produced staggered, often temporary outcomes that forced the administration to litigate, negotiate with Mexico, or pursue alternative regulatory routes [4] [5] [6].
1. MPP: lower-court injunctions, the Fifth Circuit fight, and the Supreme Court reversal
The Migrant Protection Protocols saga began with a Texas federal judge, Matthew J. Kacsmaryk, ordering the government to restart MPP and to implement it “in good faith,” a ruling the Fifth Circuit initially affirmed and that compelled the Biden team to engage in extraordinary diplomatic steps to relaunch the program [4] [1]. That lower‑court trajectory was interrupted by the Supreme Court’s June 30, 2022 decision holding that DHS’s termination of MPP did not violate the Immigration and Nationality Act and treating the termination memo as final agency action, a ruling that rejected the claim that MPP was mandated by statute and stressed executive authority over foreign relations [7] [1]. Even after that 2022 decision, litigation and procedural skirmishes continued until a later high‑court decision in 2025 clarified that the Texas judge lacked authority to enjoin the termination and affirmed the administration’s power to end MPP, allowing the administration to finally move to terminate the program [6].
2. Title 42: public‑health rulemaking, state suits, and temporary Supreme Court stays
Title 42 expulsions rested on a CDC public‑health order, so attempts to terminate the policy ran into challenges that framed the question as administrative‑procedure and public‑health law rather than pure immigration law; multiple Republican‑led states sued to block the Biden administration’s planned end of Title 42, and a federal district judge in Louisiana issued a preliminary injunction preventing termination while APA claims proceeded [2] [8]. The Supreme Court intervened multiple times to pause the administration’s attempts to lift Title 42, keeping expulsions in place while state challengers pressed their standing and merits arguments, and at points the justices ordered continued enforcement pending briefing and oral argument [3] [9]. The D.C. Circuit’s decisions in family‑protection lawsuits (Huisha Huisha) also constrained Border Patrol expulsions of certain families on torture/persecution grounds, adding another layer of judicial limitation on broad expulsions [5]. Ultimately the administration ended the public‑health emergency that authorized Title 42 in May 2023 after prolonged litigation and appeals [5].
3. Administrative‑law mechanics: APA, notice, and the CDC’s formal steps
A recurrent legal constraint was the Administrative Procedure Act’s requirement that agency rulemaking not be “arbitrary or capricious” and that decisions follow proper procedures and reasoned analysis; challengers argued that the government’s termination rules failed to account for relevant impacts, and judges who sided with states enjoined terminations on those APA grounds [2]. For Title 42 specifically, courts emphasized that the CDC director must issue a formal Federal Register notice when finding that the public‑health emergency has abated, which created a procedural channel that opponents could and did litigate over [2]. Those procedural norms meant litigation could delay policy shifts even where the administration believed it had substantive authority to change course [2] [5].
4. Political, diplomatic and practical constraints that legal rulings exposed
Beyond legal doctrine, the litigation forced the administration into political tradeoffs: complying with court orders to restart MPP required renewed talks with Mexico and practical capacity to detain or process people that DHS said it lacked, while court‑ordered maintenance of Title 42 prolonged a policy widely criticized by advocates as harmful and used politically by governors and state attorneys general asserting fiscal and security harms [1] [4] [8]. The result was a cycle of stop‑gap measures, new regulatory attempts (including asylum‑eligibility rules) and further suits by advocacy groups — underscoring that court rulings did not only interpret law but reshaped feasible policy options [10] [11].
5. Competing narratives, standing and hidden agendas
Courts evaluated not only legal texts but who had standing: state plaintiffs framed harms from migration as concrete injuries to justify intervention, a posture with clear political implications for federal‑state power battles [8] [3]. Advocacy groups countered by litigating on humanitarian and statutory grounds, arguing expulsions violated refugee‑protection obligations [5] [10]. Each litigant brought an implicit agenda — states seeking to preserve border controls and shift costs to the federal government, and advocates seeking to protect asylum access — and judges’ procedural rulings often reflected those competing interests as much as they did doctrinal clarity [1] [2].