The resignation adds to the setbacks to the most sweeping effort by the Justice Department to fulfill the president’s desire to take revenge against the federal officials who have investigated him.

© Mark Henle/USA Today, via Reuters

The expansion of an investigation into Fulton County’s election office reflects President Trump’s desire to prove his baseless claims that the 2020 election in Georgia was rigged.

© Salwan Georges for The New York Times

The loyalist, Dan Bishop, put his fealty to the president on display when he pressed the F.B.I. to chase investigative leads it had already rejected.

© Haiyun Jiang for The New York Times

Even in a government full of conspiracists, Kurt Olsen stands out. He made a key referral in the Fulton County, Ga., election case.

© Joe Rondone/The Republic, via USA Today Network

A newly unsealed affidavit showed that a criminal investigation into the 2020 election in Fulton County, Ga., relied heavily on claims about ballots that have been widely debunked.

© Nicole Craine for The New York Times