The en banc US Court of Appeals for the Fifth Circuit dismissed W.M.M. v. Trump on 13 August 2026, ruling the case moot and leaving the central legal question about President Donald Trump’s Alien Enemies Act invocation unresolved in federal appellate law. The court, sitting with all 17 judges, acted in case No. 25-10534.
The dismissal turned on a procedural point: all three named plaintiffs had been deported by the government under statutory authority separate from the Alien Enemies Act of 1798, removing the live controversy necessary to sustain the appeal.
The Legal Challenge to the Alien Enemies Act Invocation
Trump issued Proclamation No. 10903 on 15 March 2025, invoking the Act to detain and remove Venezuelan nationals the administration claimed were members of Tren de Aragua, which the State Department had designated a foreign terrorist organisation. More than one hundred people were summarily deported to a prison in El Salvador. It subsequently emerged that 75% of those deported had no criminal record, and the administration acknowledged that at least one person was removed in error, according to the Brennan Center for Justice.
The Act permits detention and deportation of foreign nationals of relevant countries whenever there is ‘a declared war’ or ‘any invasion or predatory incursion’ against the territory of the United States. Before Trump’s proclamation, US presidents had invoked the Act only three times, each during an active conflict: the War of 1812, the First World War, and the Second World War.
A three-judge panel of the Fifth Circuit, in its 2 September 2025 preliminary injunction opinion, held the invocation unlawful. Judge Leslie Southwick wrote the lead opinion, joined by Judge Irma Carrillo Ramirez; Judge Andrew Oldham dissented. The majority stated: ‘A country’s encouraging its residents and citizens to enter this country illegally is not the modern-day equivalent of sending an armed, organised force to occupy, to disrupt, or to otherwise harm the United States.’ The en banc rehearing was ordered before the full court could resolve the merits, and the moot dismissal presumably vacates that panel opinion.
District courts in Texas, Colorado, and New York had also ruled against the administration’s use of the Act, questioning Tren de Aragua’s alleged ties to the Venezuelan government and noting that the United States is not at war.
The Supreme Court and the Scope of Judicial Review
In Trump v. J.G.G., 24A931, decided on 7 April 2025, all nine Justices of the Supreme Court of the United States agreed that individuals subject to detention and removal under the Act are entitled to judicial review on questions of statutory interpretation, constitutionality, and whether the individual is in fact an alien enemy aged fourteen or older, citing Ludecke v. Watkins, 335 U.S. 160 (1948). The Court stopped short of ruling on the merits of the invocation itself.
The en banc Fifth Circuit opinion also references A.A.R.P. v. Trump, 605 U.S. 91, 98-99 (2025), in which the Supreme Court directed the en banc court to address due process questions as part of resolving the detainees’ appeal, per the Fifth Circuit opinion. That directive now also goes unanswered.
Concurring Judges Urge Deference to the Executive
Judge James Ho, in a concurring opinion, argued the court should have reached the merits and ruled that the president is entitled to absolute deference when he determines that an invasion has occurred. The breadth of that position emerged at oral argument, when Chief Judge Jennifer Elrod asked whether it would permit the president to invoke the Act in response to the ‘British Invasion’ of rock stars such as The Beatles. Department of Justice attorney Drew Ensign conceded the answer was yes.
Judge Ho drew an analogy to declarations of war: courts do not look behind a congressional declaration to assess whether a genuine war exists, he argued, and the same deference should apply to a presidential proclamation of invasion. The flaw in the analogy is structural. A congressional declaration of war is constitutionally sufficient to create a legal state of war regardless of prior events. An ‘invasion,’ by contrast, is a factual condition in the world, not a political determination that the Constitution commits to any single branch. Converting it into a presidential blank cheque would transform emergency powers designed for extreme circumstances into authority exercisable at will, contrary to both the text of the Act and the Constitution’s original meaning.
Judge Oldham, whose concurrence references his prior dissent at 154 F.4th 207, 240-312, similarly argued for a ruling on the merits favouring executive deference, but offered no new analysis beyond his earlier solo opinions.
Litigation over the Act continues across multiple circuits. Subject to any onward appeal or fresh petition, the question of whether illegal migration and drug trafficking can constitute an ‘invasion’ under the Act remains open in the Fifth Circuit and is a candidate for Supreme Court review in the coming term.
