This photo shows an envelope containing a 2018 census letter mailed to a U.S. resident as part of the nation's only test run of the 2020 Census. (Michelle R. Smith/AP)

In closing arguments Thursday in a trial over the Trump administration’s plan to add a citizenship question to the 2020 Census, plaintiffs’ attorneys accused government officials of conspiring to disenfranchise immigrant communities, while government attorneys said there was nothing unusual or inappropriate about the way top officials had gone about adding the question.

The trial, which opened last month in the U.S. District Court for the District of Maryland in Greenbelt, addresses two of seven lawsuits challenging the addition of the question, which Commerce Secretary Wilbur Ross announced in March.

Lawyers for the plaintiffs, which include immigrant civic organizations as well as U.S. citizens who live in areas with large immigrant populations, said adding the question would harm their clients by producing an undercount that. In adding the question, government officials had conspired to deny minority groups their equal rights, the lawyers also said, adding that the evidence “paints a devastating picture of administrative irregularity.”

In earlier testimony, public policy experts, statisticians, immigrant leaders and a former Census Bureau director said the question would likely produce a less accurate count. Plaintiffs’ attorneys also focused on internal documents indicating that Ross pushed the Justice Department to request the question and was not, as he testified last spring to Congress, “responding solely to the Department of Justice request.”

In court on Thursday, plaintiffs’ attorneys reviewed analyses by experts inside and outside the Census Bureau that estimated the question would result in a decrease in the self-response rate.

Noting that the bureau’s chief scientist and others at the bureau were among those warning against the question, Ben Duke, a lawyer with the firm Covington Burling, which represents the plaintiffs, said, “When the only evidence you have from your experts points in only one direction, then you have to have a compelling reason” to go against them.

That reason, plaintiffs’ lawyers said, was political.

Referring to a timeline of events around Ross’s March announcement, the lawyers said that he discussed the question with White House chief strategist Stephen K. Bannon and then-Kansas Secretary of State Kris Kobach, soon after Trump took office and months before the Justice Department request. Ross also expressed frustration, reflected in internal emails, that the Justice Department was not making the request quickly enough.

After the Justice Department made the request in December 2017, the acting Census Bureau director asked for a meeting with the DOJ to discuss alternatives to the question, but the meeting was canceled by then-Attorney General Jeff Sessions, according to internal documents.

Emails from Trump’s reelection campaign promoting the question were offered as further evidence that it was politically motivated.

The involvement of so many political players, along with emails indicating Ross did not fully understand basic workings of the survey (at one point he asked a subordinate whether noncitizens were counted), supported the argument that others were behind the decision, said Denise Hulett, lead attorney with the Mexican American Legal Defense and Educational Fund, which represents several plaintiffs in the case.

“He was a banker; this notion that he came up with this idea on his own is preposterous,” she said. “ Our view is that the objective was to exclude noncitizens from the apportionment base . . . to exclude noncitizens from political representation even if it resulted in a less accurate census.”

Government attorney Josh Gardner argued that asking about citizenship on the census has “a lengthy historical pedigree” and said Ross’s acting against the recommendation of his subordinates was “of no moment” because the secretary believed citizenship data was crucial to helping enforce the Voting Rights Act.

A question about citizenship was asked on decennial census forms through 1950; since then, it has been asked on longer Census Bureau surveys that sample a small fraction of the U.S. population.

Gardner said the plaintiffs’ lawyers had not proven a reduction in data quality would be attributable specifically to the addition of a citizenship question and that the lawyers had failed to disaggregate it from other factors such as the current environment around immigration, which is more hostile than in previous census cycles.

He described the plaintiffs’ expert witnesses as “a house of cards,” saying they relied on each other’s flawed analyses.

Gardner also disputed that there was anything suspicious about Ross’s behavior.

“A new cabinet secretary pushing his staff to get things done quickly, having a policy preference” and collaborating with others in the government was not unusual, he said. “There’s nothing wrong with trying to get things done in Washington.”

Debate at the trial centered on whether Ross believed the government’s reason for wanting the question added: namely to help enforce the Voting Rights Act and whether he had already made up his mind about the question when he was meeting with experts and lawmakers about it. Litigants against the question had sought to depose Ross about his motives, but the Supreme Court shielded him from questioning.

Last month, a judge in New York ruled against the government in a similar trial brought by multiple states, cities and organizations. The Supreme Court last week said it would decide on an appeal in that case by the end of June.

But even if the high court were to decide in favor of the government in that case, it would not make the Maryland trial moot because it includes charges that the New York trial did not, Hulett said, such as plaintiffs’ loss of political representation, and intentional discrimination and conspiracy. If the Supreme Court were to consider the discrimination charges, its level of scrutiny would go up, Hulett said.