Trump, who has argued that the citizenship question is needed to accurately count the population, has pledged to delay the decennial population survey manded by the U.S. Constitution to respond to the Supreme Court's ruling.
JudgeJesse Furman ruled Tuesday, saying lawyers must cite satisfactory reasons for withdrawing.
Hazel said on Wednesday that he shared similar concerns that the NY judge, U.S. District Judge Jesse Furman, expressed.
The federal judge overseeing the census case in the Southern District of NY has blocked the government's motion to withdraw its team of lawyers who had been working on the case previously.
Furman also noted he is not satisfied with the administration's "mere" expectation that switching out lawyers while the legal battle continues would not be disruptive.
A NY judge says the Justice Department can't change lawyers so late in the dispute over whether to add a citizenship question to the 2020 census.
It's normal for attorneys to give reasons to "come and go on cases", said Justin Levitt, a former top official in the Justice Department's Civil Rights Division.
Similar requests to change lawyers are pending before federal judges in California and Maryland, too. Some saw the decision to replace the attorneys as a sign that the Trump administration was treading on shaky legal ground and did not want to make further representations to the court.
He also noted that government lawyers must submit written arguments in the case in just three days, and that the department had previously called for expediting the case in order to resolve the dispute and get the census printed. "Could this be a first?", Trump tweeted Tuesday night.
Judges usually allow attorneys to withdraw from ongoing cases for an illness, a death in the family or "some extenuating circumstances", according to Carl Tobias, a law professor at the University of Richmond's School of Law.
Hazel stressed "the need for a transition of counsel that does not disrupt the orderly administration of justice". "Federal judges abhor counsel not being clear with the courts". He then instructed the Justice Department to find a way to ensure the question was added to the census.
Dale Ho, an attorney with the American Civil Liberties Union who is representing some of the plaintiffs in the case, said 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".