U.S. House Democrats asked a federal judge Tuesday to order the Trump administration to turn over documents related to the abandoned bid to add a citizenship question to the 2020 census, opening a new front in litigation against a president who has refused to cooperate with a number of congressional probes.

Teaming up with the law firm Debevoise & Plimpton, lawyers for the House Oversight and Reform Committee said the Trump administration has defied subpoenas seeking "critical evidence," including unredacted communications between the Justice Department and the Commerce Department.

"Despite the committee's extensive efforts at accommodations, Secretary Ross and Attorney General Barr have refused to provide these critical documents and communications," House Democrats argued in their court filing. House Democrats noted that their July vote to hold Ross and Barr in contempt over their refusal to provide documents related to the Trump administration's failed efforts to include the citizenship question on the upcoming decennial survey.

The lawsuit came a day after House Democrats scored a key victory in Washington's federal trial court, where U.S. District Judge Ketanji Brown Jackson ruled that former White House counsel Donald McGahn was required to comply with a congressional subpoena for his testimony. Minutes after that decision, the U.S. Supreme Court dealt House Democrats a setback, blocking a separate subpoena seeking access to the president's financial records.

The Justice Department said in a statement about the new lawsuit:

"The Department of Justice worked for months to supply thousands of documents to accommodate Congress's requests. Additionally, many document at issue were held privileged by a federal court. This lawsuit is nothing more than a political stunt. While the Oversight Committee plays games, the Department will continue its critical work of pursuing justice and ensuring safety for all Americans." 

For their latest lawsuit against Trump, House Democrats received help from a Debevoise & Plimpton team that includes David O'Neil, a partner in the firm's white-collar defense practice who was a leader in the Justice Department's criminal division under the Obama administration. The Debevoise team includes associates Laura O'Neill and Nathaniel Johnson, and counsel Anna Moody.

The collaboration marked only the latest instance of a major U.S. law firm providing free legal help to House Democrats in legal action against Trump.

House Democrats have leaned on major U.S. law firms to help sue the Trump administration. They turned to Sidley Austin in a lawsuit challenging the Trump administration's move to divert military funds for a wall on the southern border. The law firms Munger, Tolles & Olson and Hogan Lovells also have pro bono arrangements with the House, offering free legal assistance that stands in contrast to the steep legal bills House Republicans racked up when they received outside help to sue the Obama administration under former Speaker John Boehner.

In its lawsuit Tuesday, House Democrats said they have exposed much about the "true origins" of the effort to add a citizenship question to the 2020 census, despite the Trump administration's reluctance to hand over records.

House Democrats said their investigation revealed evidence showing that the Trump administration was moving to add the citizenship question before December 2017, when the Justice Department sent the Commerce Department a letter seeking its inclusion on the decennial survey. Commerce Secretary Wilbur Ross has pointed to that letter to justify including the question in the census, testifying at one point that he decided to add the query "solely" in response to the Justice Department's request.

Wilbur Ross, U.S. commerce secretary. Photographer: Andrew Harrer/Bloomberg

House Democrats said Ross had, in fact, pushed to include the question on the census from the time he took office. In June, the U.S. Supreme Court rejected the Commerce Department's stated reason for including the question as "contrived."

Several Big Law firms have recouped millions of dollars in legal fees for the roles they played in suing the Trump administration over the citizenship question. Cases unfolded in New York, California and Maryland federal trial courts. A Manhattan federal trial judge is weighing the plaintiffs' demand for sanctions against the Trump administration over alleged litigation abuses there.

Although the Trump administration has dropped plans to include the citizenship question, House Democrats said they have identified several other "live" concerns about the census, including the potential for political influence on what is supposed to be a nonpartisan counting of the U.S. population. House Democrats said they are pursuing records not only as part of their oversight duties but also to inform any legislative fixes to the census process.

"The stakes for Congress and the American people could not be higher, nor the consequences of the ongoing injury more profound," House Democrats said in Tuesday's lawsuit. "The 2020 census will have at least ten years of direct effect on the composition of the House by determining population counts, as well as on the methodology by which the House determines the apportionment of federal funds to the states. If there is maladministration of the 2020 census, the effects will be felt for decades, and once complete, the damage to the Census cannot be undone."