A Timeline of the Trump Administration’s Use of the Alien Enemies Act

In the 36 days since President Trump invoked a powerful wartime law to deport Venezuelan migrants accused of gang membership, a complex and high-risk legal battle has played out in the federal courts.

The Supreme Court has weighed in twice, issuing orders limiting the government’s use of the law, the Alien Enemies Act of 1798. The court’s latest order, which came around 1 a.m. on Saturday, blocked the deportations of Venezuelans held in Texas hours after the American Civil Liberties Union said the Trump administration was preparing to expel them without due process.

At times, the Trump administration has been accused of disregarding judicial orders as it proceeds with its immigration policies and deportation efforts, deepening legal scholars’ concern that the country could be facing a constitutional crisis.

Here is a timeline:

March 14: The Trump administration issued an executive order invoking the Alien Enemies Act, but the order was not immediately made public. The proclamation said that the government was targeting the violent Venezuelan street gang Tren de Aragua, which it said was threatening an invasion of the United States. The Alien Enemies Act allows the government to detain and expel immigrants age 14 or older without a court hearing when the United States is invaded or at war. It is the fourth time the law has been invoked in American history.

March 15: Fearing that the Trump administration was preparing to immediately expel Venezuelans in custody without hearings, the A.C.L.U. filed a lawsuit in federal court in Washington seeking to block the president from invoking the law. The same day, the administration published the executive order. In a hastily scheduled virtual hearing, a federal judge in Washington, James E. Boasberg, was told by the A.C.L.U. that planes were leaving the United States with Venezuelans. He ordered the government not to deport anyone under the law and to return any planes that had already taken off, “however that’s accomplished.”

March 16: On social media, El Salvador’s president, Nayib Bukele, published a video of men being led off a plane in handcuffs and taken into a prison in his country. Mr. Bukele posted an article about Judge Boasberg’s order and wrote, “Oopsie… Too late.” The Trump administration insisted it did not violate Judge Boasberg’s order. The White House press secretary, Karoline Leavitt, said in a statement that federal courts “have no jurisdiction” over the president’s handling of foreign affairs.