The inquiry has sought to link disparate criminal inquiries into the president as a multiyear scheme to damage his political prospects.

© Tom Williams/CQ Roll Call, via Associated Press

The subpoena of Daniel C. Richman is the latest move in a persistent campaign to go after James B. Comey, one of President Trump’s most reviled political adversaries who has already been indicted twice.

© Jared Soares 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

Mr. Blanche’s actions are meant to demonstrate progress on the president’s priorities, chief among them payback.

© Chip Somodevilla/Getty Images

The reversal came after the Justice Department replaced a career prosecutor with a loyalist to President Trump in the administration’s effort to charge the former C.I.A. chief with a crime.

© Al Drago/The New York Times

A former lawyer for President Trump’s campaign, Joseph diGenova, is said to be planning to split time between Miami and Fort Pierce, where a grand jury overseen by a Trump-favored judge sits.

© Tom Williams