A conservative former federal judge, J. Michael Luttig, said he believes President Trump is “declaring war” on the judicial system.

Luttig, who was appointed by former President George H.W. Bush and served on the U.S. Court of Appeals for the Fourth Circuit from 1991 to 2006, criticized the president in an op-ed published Sunday in The New York Times.

“President Trump has wasted no time in his second term in declaring war on the nation’s federal judiciary, the country’s legal profession and the rule of law,” Luttig wrote.

The Trump administration is battling a federal judge who sought to stop the deportation of nearly 300 alleged Venezuelan gang members.

Judge James Boasberg ordered the plane not to leave the U.S. or to turn around if they already had.

He’s pressed the administration on the timing of the flights after the American Civil Liberties Union suggested they defied his court order and deported them anyway.

The Trump administration said it complied because the planes left U.S. territory by the time the order was issued.

Trump has sharply criticized Boasberg and has called for him to be impeached. Attorney General Pam Bondi claimed Boasberg had “no right” to be asking those questions.

The entire altercation has put a spotlight on the executive branch’s attempts to skirt judicial power.

Boasberg is not the first judge Trump and his allies have called to be impeached. He has called for impeachment for the people who investigated his legal cases both in court and Congress.

“It’s no secret that he reserves special fury for the justice system because it oversaw his entirely legitimate prosecution for what the government charged were the crimes of attempting to overturn the 2020 presidential election and purloining classified documents from the White House, secreting them at Mar-a-Lago and obstructing the government’s efforts to reclaim them,” Luttig wrote.

Luttig argued that Trump is going to plunge the country into a constitutional crisis if he does not reverse course, and will likely become very unpopular with the American people.

He later highlighted the pushback from Supreme Court Chief Justice John Roberts, rebuking Trump’s call for Boasberg to be impeached.

“No one wants murderers or other criminals to be allowed to stay in this country, but to rid the country of them the president first must follow the Constitution,” Luttig argued. “Judge Boasberg doesn’t want to assume the role of president; the president wants to assume the role of judge.”

“If Mr. Trump continues to attempt to usurp the authority of the courts, the battle will be joined, and it will be up to the Supreme Court, Congress and the American people to step forward and say: Enough,” he wrote.

The Hill reached out to the White House for comment.