Voting rights activists argue that newly discovered 2015 correspondence between a GOP redistricting expert and a current Census Bureau official bolster arguments that discrimination motivated efforts to add a citizenship question to the 2020 population survey.

The plaintiffs, who successfully challenged the question in a Maryland federal court, said in a filing late Friday that the email exchange between the late Republican consultant Thomas Hofeller and the Census Bureau official was discovered earlier this week. They say the documents give a federal judge, who previously ruled in their favor, latitude to re-examine whether Commerce Secretary Wilbur Ross intended to discriminate against minorities by adding the citizenship question to the 2020 census.

While U.S. District Judge George Hazel issued a ruling in April to block the addition of the census question, he said the Maryland plaintiffs failed to prove that their equal protection rights were violated because they hadn’t shown that Ross and other officials acted with discriminatory intent.

Plaintiffs, citing the new documents, say the judge should reconsider on the equal protection question.

“The trial record and the Hofeller documents both reveal that the central purpose of adding a citizenship question was to deprive Hispanics and noncitizens of political representation,” the plaintiffs argue, adding that the evidence “explains precisely why Secretary Ross pressed ahead with adding the citizenship question in the face of … evidence that it would cause a disproportionate undercount of noncitizens and Hispanics.”

Trump administration lawyers argued in filings before Hazel this week that the newly discovered documents don’t justify the “extraordinary request” to reopen a case already decided in the plaintiffs’ favor.

The Commerce Department issued a statement today saying that Hofeller played no role in Ross’s decision to add the citizenship question: “All of Plaintiffs’ conspiracy theories are outlandish and should be disregarded.”

The U.S. Supreme Court is currently considering the citizenship question after Hazel’s ruling and similar ones by judges in New York and California who concluded the question was improperly added to the U.S. census for what would be the first time since 1950. The high court could rule by July.

Voting rights groups have argued that the citizenship question would serve to strengthen GOP congressional representation and funding for areas where mostly Republicans reside by suppressing the count of immigrants. States with large numbers of immigrants tend to vote Democratic.

The U.S. Constitution specifies that congressional districts should be based on how many people — not citizens — live in an area.

The Maryland plaintiffs argued in a June 3 filing that the new trove of Hofeller documents, first revealed in late May as part of the New York case, show that he played a role in drafting Justice Department documents regarding the citizenship question, and that Hofeller had explained in a separate memo that the addition would help “Republicans and Non-Hispanic Whites.”

The Hofeller documents were discovered when his estranged daughter found four external computer hard drives and 18 thumb drives in her father’s Raleigh, North Carolina, home after his death last summer.

The challengers to the citizenship question have also cited the documents in New York federal court and at the Supreme Court in their effort to keep the question off the 2020 census.

The newer documents, unearthed this week during a further forensic analysis, show how far back the discussions about adding the citizenship question go, the plaintiffs argue. Attached to their Friday filing is a January 2015 email from Christa Jones to Hoffeler saying that a 2015 test of census data collection presented “an opportunity to mention citizenship as well.” Jones is now chief of staff to the deputy director of the U.S. Census Bureau.

The plaintiffs argue that “newly discovered documents suggest that Hofeller had also long been in contact with a highly-ranked Census employee, who knew of Hofeller’s interest in a citizenship question (and in fact suggested opportunities for him to raise that interest with the Census Bureau).”

The Justice Department has denied that the new documents show discriminatory intent. A spokeswoman declined further comment today.

A spokesman for the Census Bureau didn’t respond to a question seeking comment.

The Justice Department lawyers wrote in a filing in the Maryland case that “there is no basis to revisit this Court’s prior determination that it could not ‘connect the dots’ between the Secretary’s decision and evidence of third parties’ animus.”

They also argue that the evidence cited is not new, wouldn’t have changed the outcome of the case and could have been previously brought to the court’s attention “if Plaintiffs had exercised due diligence.”

This story has been corrected to reflect that Jones reports to the deputy director of the U.S. Census Bureau.