The case in front of the Fifth Circuit emerged from an emergency petition filed by the A.C.L.U. seeking to stop the Trump administration from deporting a group of Venezuelan men from the Bluebonnet Detention Facility in Anson, Texas.
The Sinaloa Cartel, the world’s most-feared fentanyl trafficker, is reeling from an internal war and a U.S.-Mexican crackdown. Its fate could upend global criminal networks.
The dueling moves reflected how federal law enforcement officers have at times been put in the position of pursuing the Trump administration’s shifting political agenda.
The decision to return and prosecute Kilmar Armando Abrego Garcia, who is accused of belonging to MS-13 and who had been wrongly deported to El Salvador, provided Trump officials with an offramp.
Top gang leaders being sent back to El Salvador were part of a lengthy federal investigation that has amassed evidence of a corrupt pact between the Bukele government and MS-13.
Mr. Bukele, the Salvadoran president, agreed to help the White House carry out one of Mr. Trump’s signature policy agendas — the mass deportation of immigrants — by allowing scores of them to be housed inside his prisons where they would likely be beyond the reach of the U.S. justice system in exchange for millions of dollars and a request for the return of about a dozen senior members of MS-13 who were facing American charges.
In April, the Trump administration sought to use the Alien Enemies Act to deport a group of Venezuelans held at the Bluebonnet Detention Facility in Anson, Texas.