WASHINGTON — A federal judge in New York on Tuesday rejected the Justice Department’s request to switch its legal team midway through a case challenging the Trump administration’s effort to add a citizenship question to the 2020 census.
The sharply worded order, by United States District Judge Jesse M. Furman, potentially further hobbles President Trump’s battle on behalf of the citizenship question, which already appeared to be in serious jeopardy.
On Sunday, the Justice Department said it was replacing the legal team defending the citizenship question. It offered no explanation for the change, which came in the middle of a prolonged clash over whether the administration’s arguments for adding the question could be believed.
But on Tuesday, as a new team of lawyers began to notify the court of its appearance in the case, Judge Furman barred the old lawyers from leaving until they met a legal requirement to satisfactorily explain their departure and show that it would not impede the case.
“Defendants provide no reasons, let alone ‘satisfactory reasons,’ for the substitution of counsel,” he wrote, adding that their written assurance that the switch would not disrupt the case “is not good enough.”
If the department wishes to continue with the switch of legal teams, the judge wrote, the lawyers must provide sworn affidavits explaining their departures and remain under the court’s jurisdiction should they be required to return.
The American Civil Liberties Union and other plaintiffs had asked the judge on Monday to block the Justice Department’s reassignment of the case without providing a reason for the withdrawal. On Tuesday the group said it still had questions about the move.
“The Justice Department owes the public and the courts an explanation for its unprecedented substitution of the entire legal team that has been working on this case,” said Dale Ho, the A.C.L.U.’s lead attorney on the case. “The Trump administration is acting like it has something to hide, and we won’t rest until we know the truth.”
The Justice Department declined to comment.
On its face, Judge Furman’s order only enforces a court rule governing changes of legal counsel. Practically, however, it presents the department with a difficult choice: Either reverse course and leave its old legal team in place, or produce sworn explanations that could prove both embarrassing and damaging to the administration’s case.
The department’s legal campaign had already undergone head-snapping changes in strategy this month. Department lawyers first said they were abandoning the case in the face of a Supreme Court ruling blocking the question, only to reverse course a day later and say they were exploring a “legally available path” to restoring the question on orders of Mr. Trump.
But that handed opponents of the citizenship question a legal opening: In a motion in Judge Furman’s court last week, they argued that the government had repeatedly said the lawsuit had to be resolved by June 30, when the printing of the 2020 census forms had to begin. The department’s announcement that it would continue to press for the question in July belied that explanation, opposition lawyers said.
They also suggested that the administration had set a false deadline for resolving the case to keep opponents from uncovering evidence that the citizenship question had been driven by a desire to help the Republican Party gain power when census figures are used to draw new political boundaries in 2021. The challengers said they would pursue sanctions against the defense for its conduct.
The Justice Department announced the switch in legal teams two days later on Friday. While the department has not explained the change, multiple people familiar with the case have said that the lawyers resigned from the lawsuit out of ethical concerns and a belief that the suit was unwinnable.
Those people have said that many of the lawyers did not see a path forward on the case, given that any argument would most likely contradict statements made in district courts and the Supreme Court that the administration had to have a decision by June 30.
But were that explanation given to Judge Furman, it would undermine any future arguments made by the Trump administration as it continues to find a way to put the citizenship question onto the census.
“They are absolutely in a bind,” said Neal Katyal, a partner at Hogan Lovells and the former acting solicitor general. “They can’t answer the question without gutting what Trump and Barr are trying to do. They can try to avoid being forthcoming, which is increasingly the modus operandi of Trump’s Justice Department. But that move will fail in the courts, as today’s decision indicates.”
The census fight has become an embarrassing issue for the Justice Department.
William Barr, the attorney general, told The New York Times on Monday that he believed the department could find a legal path to adding the citizenship question to the census.
Mr. Barr also said he believed the team that had worked on the census question through the Supreme Court ruling had done exemplary work. He added that he had heard from James Burnham, who had been in charge of the case, that a number of lawyers who had been working on the census issue for a long time “probably prefer not to stay at this new phase in the litigation.”
“We decided not to put them in that position,” Mr. Barr said.