Jeffrey A. Rosen led the Justice Department during the final month of the Trump administration, when President Donald J. Trump and his allies most aggressively pressed federal and state officials to reverse his defeat in the 2020 presidential election.
Mr. Rosen, who served as acting attorney general, is expected to help the Jan. 6 committee paint a more detailed picture of efforts by Mr. Trump and his allies to arm the Justice Department in their efforts to void the election.
He is also expected to talk about the dramatic showdown that took place in the Oval Office on January 3, 2021, when senior Justice Department officials said they and other members of the department would resign en masse if Mr. Trump replaced Mr. Rosen with Jeffrey. Clark, who headed the department’s civil division and was willing to help Mr. Trump in his efforts to overturn the election.
In a statement he prepared for the committee, Rosen said the Justice Department had never found credible evidence of voter fraud, underscoring one of the committee’s key points. “Some argued to the former president and the public that the election was corrupt and stolen,” Mr. Rosen wrote. “That view was wrong then, and it is wrong now, and I hope our presence here today will help reaffirm that fact.”
While Mr. Trump’s efforts to install Mr. Clark at the top of the Justice Department have been well-documented by previous investigations, including one by the Senate Judiciary Committee, Mr. Rosen could help the Jan. 6 committee flesh out more information, including about Mr. Trump’s push for a special counsel to investigate voter fraud and his direct involvement in the Justice Department pressure campaign.
Mr. Rosen served as an official in the Department of Transportation and the Office of Management and Budget during the George W. Bush administration, when he struggled to rein in the regulatory authority of the federal government, which many Republicans considered excessive. He returned to the Transportation Department under Mr. Trump, then joined the Justice Department to replace Rod J. Rosenstein, the assistant attorney general who oversaw the Russia investigation.
Mr. Rosen was overshadowed by Attorney General William P. Barr, who was close to Mr. Trump. But Mr. Barr left after the election, when the president attacked him for refusing to support his allegations of fraud, leaving Mr. Rosen to defend the department.