Curtis Bradley, an international law professor at the University of Chicago, highlighted Trump’s ongoing legal battle with the American Civil Liberties Union over his use of the Alien Enemies Act to rapidly detain and deport Venezuelans alleged to be members of the Tren de Aragua gang. The statute gives the president extraordinary power to expel citizens of enemy nations, when there is a declared war or in the event of an “invasion” or “predatory incursion.”

In September 2025, the conservative U.S. Court of Appeals for the Fifth Circuit ruled 2-1 that there was no existing emergency justifying the wartime power. That decision, currently being reviewed by the full Fifth Circuit, is certainly a candidate for Supreme Court review, Bradley said.

“If they hold against him, I think they’ll have to say this doesn’t constitute an emergency,” said Bradley, who previously clerked for Supreme Court Justice Byron White.