A federal judge on Thursday barred the Trump administration from deporting any Venezuelans from South Texas under an 18th-century wartime law.

U.S. District Court Judge Fernando Rodriguez Jr. is the first judge to rule that the Alien Enemies Act cannot be used against people who the Republican administration claims are gang members invading the United States.

"Neither the Court nor the parties question that the Executive Branch can direct the detention and removal of aliens who engage in criminal activity in the United States," wrote Rodriguez. But, he said, "the President's invocation of the AEA through the Proclamation exceeds the scope of the statute and is contrary to the plain, ordinary meaning of the statute's terms."

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In March, President Donald Trump issued a proclamation claiming that the Venezuelan gang Tren de Aragua was invading the U.S. He said he had special powers to deport immigrants, identified by his administration as gang members, without the usual court proceedings.

The Alien Enemies Act has only been used three times before in U.S. history, most recently during World War II, when it was cited to intern Japanese-Americans.

The proclamation triggered a flurry of litigation as the administration tried to ship migrants it claimed were gang members to a notorious prison in El Salvador.

Rodriguez's ruling is significant because it is the first formal permanent injunction against the administration using the AEA and contends the president is misusing the law.