The US Justice Department on Monday sought to remove a judge who ordered the Trump administration to explain whether it defied a court order by deporting hundreds of Venezuelans the White House says are violent criminals, Reuters reported.

The Trump administration deported more than 200 Venezuelans it says were members of Tren de Aragua, a Venezuelan gang that has been linked to kidnapping, extortion and contract killings, to El Salvador over the weekend, even as a judge temporarily blocked it from using a wartime law to carry out the deportations.

Several legal experts interviewed by Reuters said the flights represented a direct challenge to the judicial branch’s independence, although the White House denied that.

President Donald Trump has sought to push the boundaries of executive power since taking office in January, cutting spending authorized by Congress, dismantling agencies and firing thousands of federal workers.

On Monday, his Justice Department sought to remove the judge from the case.

The request to remove Judge James Boasberg came just before a hearing in his Washington courtroom began on the matter at 5 pm on Monday. Boasberg had instructed the government to provide details on the timing of the flights that transported the Venezuelans to El Salvador, including whether they took off after his order was issued.

At an emergency hearing on Saturday requested by the American Civil Liberties Union, a civil rights group, Boasberg issued a two-week temporary block on Trump’s use of the Alien Enemies Act of 1798 to carry out the deportations.

The White House asserted on Sunday that federal courts “have no jurisdiction” over Trump’s authority to expel foreign enemies under an 18th-century law historically used only in wartime, though it also said it had complied with the order.

In a court filing shortly before Monday’s hearing, the Trump administration said the judge’s spoken directive to return any planes carrying the migrants was “not enforceable” because it was not in a written order.

The administration said it did not violate Boasberg’s subsequent written order barring immigration authorities from removing migrants because the planes had already departed when it was issued.

“I think there’s a fundamental question to ask here, and that is: how can a judge sitting in Washington, DC, have jurisdiction over three planes filled with criminals flying over the Gulf of America?” Secretary of State Marco Rubio said on Fox News, using the term Trump prefers for the Gulf of Mexico.

Some legal experts said the plane’s location in the air was irrelevant.

Michael J Gerhardt, a constitutional law professor at the University of North Carolina School of Law, said the argument “borders on the absurd” and was “contrary to well settled constitutional law” holding that federal officials are subject to the Constitution no matter where they are.

“A governmental plane on governmental business is not in a law-free zone,” Gerhardt said, adding: “If that is not the case, then the government can simply do anything it wants to do so long as it is not operating any longer on American soil.”

With the Republican-controlled Congress largely backing his agenda, federal judges have often been the only constraint on his executive actions, putting many on hold while they consider their legality. In some cases, advocacy groups have said the administration is refusing to comply with judicial orders.

Trump has been challenging the historic checks and balances between the U.S. branches of government.

Rubio also questioned a routine norm within the federal judiciary when he complained to Fox News, “We’ve gotten out of control. All you’ve got to do is go find a judge anywhere in America and issue these orders that apply nationally.”

That standard, in which a district judge can issue an order with national authority, is not new and has been used by Trump in the early stages of litigation to block other measures he opposes.

Alien enemies act

Trump made rare use of the Alien Enemies Act, which gives the president the wartime authority to deport non-citizens whose primary allegiance is to a foreign power, to carry out many of the deportations.

It has been invoked just three times: during the War of 1812, World War One and most recently World War Two when it was used to justify the mass internment of people of Japanese, German and Italian descent.

Leavitt said there were 261 people deported in total, including 137 who were removed under the Alien Enemies Act and more than 100 others who were removed via standard immigration proceedings. There were also 23 Salvadoran members of the MS-13 gang, Leavitt said.

The Trump administration has variously described the deported Venezuelans as gang members, “monsters,” or “alien terrorists,” but has not provided evidence to back up its assertions, and the ACLU has criticized authorities for falsely applying the label.

Four Democratic senators on Monday called Trump’s use of the Alien Enemies Act for immigration enforcement an “unlawful and brazen power grab.”

“All of us, including the courts, must continue to hold this administration accountable, and prevent the Trump administration from taking us down a dark and dangerous road,” Senators Dick Durbin, Alex Padilla, Cory Booker, and Peter Welch said in a statement.