MANHATTAN (CN) – Fighting the revival of a citizenship question on the 2020 census, New York Attorney General Barbara Underwood told a federal judge Tuesday that the government is withholding evidence of how racial bias spurred the change.

U.S. District Judge Jesse Furman advanced the lawsuit in July, finding that the challengers made a “strong showing of a claim of bad faith” by Secretary Wilbur Ross.

Though Ross testified in Congress that he added the citizenship question at the request of the Department of Justice to enforce the Voting Rights Act, information later emerged showing that Ross considered making the change some 10 months earlier, immediately after his appointment in February 2017.

As the case winds through discovery now, Underwood said in a 5-page letter to Furman Tuesday evening that the government improperly invoked privilege over 32 documents. Joined by Arnold & Porter attorney Daniel Jacobson, Underwood said several of the disputed emails go to the heart of the disconnect in Ross’ claims.

“Ten documents relate to congressional testimony or other communications with Congress and the media, which are relevant to whether there were efforts to mislead the public with a pretextual explanation,” Underwood wrote.

These records were created or received by Ross and three other senior officials at the Commerce Department: chief of staff Wendy Teramoto, undersecretary Karen Dunn Kelley and director Earl Comstock.

Teramoto’s records revealed that she exchanged emails with Kansas Secretary of State Kris Kobach, a staunch anti-immigration hardliner who earned a rebuke from a federal judge that his crusade against voter fraud is thinly veiled attempt to suppress the vote of ethnic minorities that traditionally vote Democrat.

“Nice meeting you on the phone this afternoon,” Kobach wrote to Teramoto on July 14, 2017. “Below is the email that I sent to Secretary Ross. He and I had spoken briefly on the phone about this issue, at the direction of Steve Bannon, a few months earlier.”

Bannon at the time had been serving as chief strategist for the Trump White House, but he was fired a month later following white-supremacist violence in Charlottesville, Virginia. The New York Times reported that Bannon told Trump to spread the blame for the bloodshed among “many sides” — disastrous advice ultimately blamed for Bannon’s ouster.

After his White House stint, Bannon went back to his Breitbart media empire, which published multiple columns from Kobach arguing in favor of the citizenship question, which has not appeared on the census since 1950.

Teramoto claimed at her deposition meanwhile not to even know who the Kansas Republican was.

“You asked me, sir, if at the time if I knew who Kris Kobach was, and I said I didn’t,” she said under oath on Aug. 24 this year.

Teramoto’s denial that she knew Kobach is cited as one example of “obfuscation” by senior Commerce Department officials in their depositions.

“The lack of forthrightness of these senior government officials was troubling to say the least,” the letter states.

“Given the failed memories of Commerce’s senior leadership, the need for contemporaneous, documentary evidence is paramount,” Underwood added.

On top of their previous request to depose Kobach, they want Judge Furman to release the records. The Commerce Department and Secretary Ross insist that these are shielded by deliberative process privilege, which is meant to keep internal government agency communications private.

Underwood contends that the communications Ross is trying to keep secret betray his unconstitutional motivations for the census shake-up.

“They are relevant to whether defendants acted with discriminatory intent toward immigrant communities, whether defendants acted under political pressure, and whether they created a pretext to justify their decision,” the 5-page letter states.

“Some may reflect outright animus toward immigrant communities of color,” it continues.

The Commerce Department did not respond to an email seeking comment.

Underwood argued that Ross’ assertion makes a mockery of the privilege.

“The purpose of the privilege is to protect deliberations by government actors over how to best serve the American public, not ‘deliberations’ over how best to mislead the public,” her letter states. “In all events, any legitimate interest defendants have in shielding the requested documents is far outweighed by the importance of the documents to plaintiffs’ claims.”