Elizabeth OuYang, coordinator of New York Counts 2020, speaks Tuesday during a news conference outside a federal courthouse in New York. U.S. District Judge Jesse Furman says he expects to rule in the next few weeks on whether to ban a citizenship question from appearing on the 2020 Census. (Mary Altaffer/AP)

Lawyers challenging the Trump administration’s addition of a citizenship question to the 2020 Census said Tuesday that the secretary of commerce had acted above the law when he added it, and argued it would put the country’s “statistical backbone” in jeopardy.

The remarks came during closing arguments in a trial challenging the administration’s March decision to add the question to the decennial count.

In a federal courtroom in Manhattan packed with immigrant rights activists, lawyers spent several hours answering pointed questions from U.S. District Judge Jesse M. Furman, who has rejected multiple attempts to dismiss or delay the case. At one point, Furman chided the Justice Department for offering “every possible argument . . . to avoid a decision of the merits of this case.”

The plaintiffs, a coalition of several dozen states, cities and civic organizations, say the question should be removed because it will lead to a significant undercount and cheat states and cities out of funding and representation, while the government says it would not harm the count.

A central debate during the two-week trial was whether the citizenship question would serve a useful purpose. The government argued that having more granular “block-level” data would help it enforce the Voting Rights Act. But expert witnesses contradicted that, saying that, in fact, noncitizens often either leave questions about their immigration status blank or provide inaccurate answers.

Critics have called Commerce Secretary Wilbur Ross’s addition of the question a brazen political maneuver, especially since pretrial documents revealed that his decision to add it was taken in consultation with Stephen K. Bannon, the president’s former strategist, and Kansas Secretary of State Kris Kobach, who served as the vice chairman of Trump’s now-defunct voter fraud commission. Seven lawsuits have been filed challenging the question.

Lawyers for New York Attorney General Barbara Underwood and the American Civil Liberties Union argued that the claim about voting rights was a pretext. They said Ross was motivated in part by the understanding that a citizenship question could help exclude noncitizens from the apportionment process by undermining trust in the survey, particularly as immigration has heated up as a political flash point since the last census.

Matthew Colangelo, a lawyer with the New York attorney general’s office, said Tuesday that Ross had behaved recklessly when he pushed ahead with adding the question even though it was clear that Latinos and foreign-born individuals would probably remove themselves from the census process as a result. “The secretary of commerce is not above the law,” he said.

“The outcome of this trial will affect every community in this country,” he said, adding that census data is the “statistical backbone” of the government’s data about the population. “By corrupting this data, we are undermining all of that.”

The once-per-decade population count determines everything from congressional seats to the allocation of $800 billion in federal money for schools, roads and other services. Many heavily immigrant jurisdictions are led by Democrats, and lower response rates could reduce representation in those areas.

The Trump administration has denied that the question is politically motivated. It has made multiple requests for the trial to be blocked or delayed, some reaching the Supreme Court, which has so far declined to stop the litigation.

At trial, the government argued that Ross ordered the addition of the question to assist the Justice Department in its enforcement of the Voting Rights Act and that any undercount resulting from the question could be mitigated during the nonresponse follow-up process.

The government’s only witness, Census Bureau chief scientist John Abowd, said analyses of responses to the American Community Survey, which does ask about citizenship, have found that about 30 percent of noncitizens provide incorrect information about their immigration status. That survey, which is not used to count the U.S. population, reaches about 2.6 million Americans annually.

During more than two days of testimony, Abowd said repeatedly that he did not agree with Ross’s decision to add a citizenship question to the census because of its impact on the overall data.

But Abowd, who also serves as the bureau’s associate director for research and methodology, said he believed the gap in the response rate could be resolved in the follow-up process and said there was no empirical evidence to suggest otherwise.

On Tuesday, Brett Shumate, a lawyer with the Justice Department, argued that because the questionnaire goes to every single household, and because responding to the census is required by law, the government was not seeking to exclude anyone.

He added that self-response rates have been “declining for decades” and that fear of deportation, and even fear of the specific actions of the Trump administration, were present even before the decision to add the citizenship question.

Justice Department spokeswoman Kelly Laco told The Washington Post on Tuesday, “Our government is legally entitled to include a citizenship question on the census and people in the United States have a legal obligation to answer.” She said the question “ultimately protects the right to vote and helps ensure free and fair elections for all Americans.”

But Dale Ho, a lawyer for the ACLU, told The Post that the question was “an attempt to drive people into the shadows and not count them, and to exclude them from decision about political representation.”

It is illegal for the Census Bureau to release data on specific households, but immigrant rights groups say Latino and immigrant households nonetheless fear their disclosures could be used against them by Immigration and Customs Enforcement or other federal agencies. Earlier this month, documents released in another lawsuit showed administration officials appearing to suggest that the confidentiality of census data may be up for debate.

John Freedman, a lawyer for the New York Immigration Coalition, on Tuesday cited the example of the internment of Japanese Americans, who were identified with the help of census data, during World War II.

“We have a history in this country of misuse of census data,” he said, adding, “Laws can change.”

Plaintiffs’ lawyers also said the late addition of the question departs from the Census Bureau’s usual practice of researching and testing a new question for several years before adding it. Experts, including six former Census Bureau directors, have said adding it would depress the response rate.

Judge Furman said he expects to issue a ruling within weeks. The case could eventually go to the Supreme Court.