A federal judge issued a stinging rebuke of Elon Musk on Tuesday, ruling that he and the Department of Government Efficiency likely violated the Constitution by attempting to shut down the U.S. Agency for International Development.

Judge Theodore D. Chuang, an Obama appointee to the court in Maryland, ordered Mr. Musk and the DOGE to restore USAID workers’ electronic access and to stop their efforts to carry out the shutdown.

Judge Chuang specifically ordered them to preserve USAID’s headquarters at a federal office building in Washington in preparation for a final ruling that could fully restore the agency.

The ruling is one of the farthest-reaching judicial rebukes yet of Mr. Musk, saying it appeared he was the power in the administration behind the shutdown attempt.

“Thus, based on the present record, the only individuals known to be associated with the decisions to initiate a shutdown of USAID by permanently closing USAID headquarters and taking down its website are Musk and DOGE team members,” the judge wrote.

He rebuffed the administration’s argument that all the key decisions were actually made by Secretary of State Marco Rubio and Peter Marocco, the State Department official now in charge of foreign assistance.

Judge Chuang issued an injunction blocking DOGE from further meddling with USAID.

His ruling goes to the heart of questions about Mr. Musk, the world’s richest man and a special assistant to Mr. Trump who is spearheading the president’s attempt to remake the federal bureaucracy.

Justice Department lawyers have denied that Mr. Musk is part of the DOGE, saying that he is instead an influential advisor to the president but wields only soft power and has no actual decision-making authority.

Judge Chuang didn’t buy that.

He kicked off his 68-page ruling by pointing to Mr. Trump’s declaration after the election that he was asking “the Great Elon Musk” to head the DOGE.

The judge also pointed out that Mr. Trump has repeatedly cited Mr. Musk as the DOGE head, contradicting the Justice Department’s arguments in court.

He cited Mr. Trump’s statement that the president would sign executive orders and hand them to Mr. Musk who would order others to “get it done.” And the judge cited Mr. Musk’s own statements, including taking credit for the USAID shutdown and for managing the personnel of the DOGE.

Judge Chuang then connected DOGE to several questionable actions across the government, including putting employees on leave at the Education Department and blocking spending at the Federal Emergency Management Agency.

USAID has become emblematic of Mr. Trump’s broader fight to slim down government.

The president says the agency had gone rogue, spending money on things that went well beyond what Congress had intended and in ways that violated Mr. Trump’s own priorities.

That ranged from funding controversial LGBTQ efforts abroad to paying for millions of dollars in food assistance for Syrian refugees that actually went to terrorist fighters in Syria.

USAID’s headquarters at the Ronald Reagan Building, blocks from the White House, was shuttered last month as employees were given 15 minutes to clear out their desks.

Since the original shutdown, Mr. Rubio said he has done his own review of the agency and decided more than 80% of its programs should be shuttered. The remainder, he said, will be run out of the main State Department.

With the injunction, Judge Chuang has now created an avenue for an appeal to the 4th U.S. Circuit Court of Appeals.

Norm Eisen, executive chair of the State Democracy Defenders Fund, which represented the challengers in the case, hailed the ruling.

“This case is a milestone in pushing back on Musk and DOGE’s illegality,” he said.