But some rank-and-file prosecutors said they saw Mr. Barr’s action as politically motivated and damaging to the department’s credibility. Several compared the move to his forcing prosecutors in February to reduce a standard sentencing recommendation for Roger J. Stone Jr., a friend of Mr. Trump, saying it would leave a lasting mark on the department…

Many current and former federal prosecutors across the country said they were shocked by the Flynn decision. But current and former department lawyers and F.B.I. officials also sent department leaders “significantly positive feedback” and “applauded the recommendation” to drop the Flynn case, said Kerri Kupec, a department spokeswoman.

The critics of Mr. Barr’s decision noted that no one who had worked on the case signed the legal paperwork effectively ending the Flynn prosecution except for Timothy J. Shea, the interim U.S. attorney in Washington. There were signs of haste. Mr. Shea mistakenly used the District of Columbia bar identification number of his predecessor.

While the ailing economy seemed to reduce the chances of a wave of resignations, some career officials quietly sounded out potential private sector jobs, fearing that their own cases could come under internal attack, said two people briefed on the matter.