The FBI and the Justice Department had no comment on Trump’s remarks that undermine the agency. Rep. Gerald E. Connolly (D-Va.), the chairman of the House government operations subcommittee, criticized Trump for a “new low in his attacks on federal employees.”

His Republican counterparts — Rep. Mark Meadows (N.C.), the ranking minority party member on the panel, and Sen. James Lankford (Okla.), chairman of the Senate federal management subcommittee — did not respond to requests for comment.

“I thought this was a totally unexpected body blow he threw at the bureau . . . just for that coarseness of the language and the emotion behind it,” said Turner, 68, a former FBI special agent in Minneapolis.

Trump’s comments do “terrible harm,” she said, because if agents knock on someone’s door and the resident “believes that we’re out to get the president or out to overthrow the government . . . we’re in deep trouble.” Citizens must know “we’re trying to do the best for this country. They’ve got to believe that.”