The Supreme Court said the administration could, for now, deport alleged Tren de Aragua members under the powerful wartime law but that it must give “reasonable notice” before deporting them so that the prospective deportees could have a chance to challenge their removals in court on an individual basis.

That decision meant that Trump administration officials could not repeat what they did on March 15, which was give little or no due process to the alleged gang members they deported under the Alien Enemies Act. The Supreme Court’s overall decision was 5-4, but its decision on the need for notice and due process was unanimous.

The Supreme Court’s decision also made clear that such a process must play out in the venue where the alleged gang members are being detained. That portion of the order served as a rebuke of the American Civil Liberties Union, which brought its lawsuit against the Trump administration in Washington, D.C., despite its five Venezuelan clients being detained in Texas.

Josh Blackman, a South Texas College of Law professor, told the Washington Examiner the ACLU “took a risk” by bringing its lawsuit in Washington. The five alleged gang members were almost flown with more than 250 others from Texas to a Salvadoran prison on March 15 before the ACLU stepped in. Blackman noted that a court in Texas, where there is a higher concentration of conservative judges, was less likely than a court in Washington to grant the emergency relief the ACLU wanted amid a fast-moving deportation operation.

“There’s nothing wrong with forum shopping, just to be very clear. Everyone does forum shopping, but there are limits on where you can bring the suit,” Blackman said. “I think the law on [habeas corpus] is pretty clear. You bring the suit where the person is being detained.”

Aaron Reichlin-Melnick, a senior fellow at the American Immigration Council, told the Washington Examiner that the Supreme Court’s decision meant that most migrants detained in preparation to be deported under the Alien Enemies Act would likely fall under the Republican-friendly 5th U.S. Circuit Court of Appeals’s jurisdiction, which encompasses Louisiana, Texas, and Mississippi.

“The overwhelming majority of ICE detention centers are in the South,” Reichlin-Melnick said, adding that “the very nature of where the jails are that people are held means that most people will be in the 5th Circuit.”

However, he cautioned that the Supreme Court’s ruling on the Alien Enemies Act was narrow and said it is “extremely likely” that the high court, and not the 5th Circuit or some other appellate court, would be the final arbiter in another case about the law.

The ACLU, for its part, moved quickly to file a new lawsuit on Tuesday in New York that abided by the Supreme Court’s order. The lawsuit cited two Venezuelans who were also plaintiffs in the original Alien Enemies Act case. Those two Venezuelans happened to have been relocated to an immigration facility in New York after Judge James Boasberg temporarily blocked the administration from deporting them.

Now that the Supreme Court has tossed out Boasberg’s order, the ACLU attorneys said, the two detainees in New York were in danger of being improperly deported under the Alien Enemies Act. They argued their clients were not gang members and that Trump did not satisfy the criteria to use the act.

SUPREME COURT LIFTS ORDER AGAINST TRUMP USING WARTIME LAW FOR DEPORTATIONS

Legal experts have emphasized the justices’ unanimous agreement that migrants facing deportation under the Alien Enemies Act were entitled to “reasonable notice” and due process but have also noted that there remain unknowns. Reichlin-Melnick said the justices were unclear about what constituted meaningful notice. The Trump administration could decide to afford migrants a day, a week, or some other duration. Regardless, the practicality of every alleged gang member being able to contact a lawyer in time to file a new lawsuit before they were deported was “going to be hard,” Rechlin-Melnick said.

“It’s possible that people will be able to get in touch with individuals who are subject to the law, but as it stands, it is only through informal networks that people are even finding out about those who might be subject to the law,” he said.

Jack Goldsmith, a Harvard Law School professor and former DOJ official, said during a video interview on Tuesday that the Supreme Court’s decision was not a “giant win for either side.” He said forthcoming lawsuits, of which there could be “hundreds,” are going to be “factually complicated.” The Supreme Court has not at this stage made any decisions on the core question of whether Trump legally implemented the Alien Enemies Act, for example.

“On the legal issues, nothing’s going to happen until the Supreme Court weighs in. The 5th Circuit can say or do what it wants,” Goldsmith said.