Administration officials said they expect the fight over using the wartime act to ultimately head to the Supreme Court.

President Trump says he’s using the 227-year-old law to crack down on Venezuela’s Tren de Aragua gang. The move is already facing a legal challenge. Here’s a look at key questions and answers about the Alien Enemies Act.

A federal judge late Saturday blocked President Donald Trump’s executive order invoking the Alien Enemies Act to deport migrants—even ordering the administration to turn around flights that had already departed—the latest in a string of court rulings against Trump and cost-cutting czar Elon Musk.