A majority of the justices concluded that the Venezuelan migrants had brought their cases in the wrong court but that they were entitled to an opportunity to challenge their removal.
The Trump administration sought to use the Alien Enemies Act of 1798 to deport more than 100 Venezuelans to the Terrorist Confinement Center prison in Tecoluca, El Salvador, last month, prompting a legal challenge.
The judge, James E. Boasberg, said he was likely to wait until next week to rule on whether the White House was in contempt of court for having ignored his order.
Judge James E. Boasberg said on Thursday that there was a “fair likelihood” that the Trump administration had violated his order to stop deporting Venezuelan migrants to El Salvador under a wartime law.