The Trump administration had other ways to make good on its corrupt bargain. Mr. Trump himself could have ordered the dismissal motion. Sure, such an intervention would be inadvisable, as Attorney General William Wirt warned President James Monroe in 1821, because “it is an impolitic relaxation of the laws and holds out an encouragement to sport and trifle with them.” But Mr. Trump has trifled before. Alternatively, Mr. Bove could have signed the motion, as he ended up doing. He clearly thought it important the filing come from New York.

I doubt this was to save travel expenses. Rather, Mr. Bove wanted to put the reputation and credibility of the Southern District behind the administration’s naked exercise of power and disregard for the rule of law. Since long before the creation of the Justice Department in 1870, U.S. attorneys’ offices around the country have served presidential purposes by mediating between Washington and the districts. Deeply embedded locally, U.S. attorneys and their assistants have sought to advance presidential and congressional goals before local federal judges and juries.

As Mr. Bove’s letter accepting Ms. Sassoon’s resignation suggests, federal prosecutors can be turned into the president’s sock puppets. Yet it is inconceivable that federal criminal law, given its depth, breadth and severity, would look the same if Congress thought it was simply handing power to a unitary executive. Moreover, Mr. Bove’s vision of prosecutorial fealty relies on an unsustainable bait and switch. Should the public see every federal prosecutor and agent as just a presidential minion, lacking professional judgment, moral compass and respect for law, the responses of judges, juries and witnesses will be simply a function of their own political preferences.

Ms. Sassoon and other Justice Department officials refused to be Mr. Bove’s sock puppets. When Judge Dale E. Ho considers whether to allow the dismissal of the charges against the mayor, Mr. Bove will have to defend his decision. Judge Ho has limited discretion and may well end up accepting the motion. But Mr. Bove, Attorney General Pam Bondi and Mr. Trump now have to own their deal. If they are proud of it, their effort to hide their involvement is curious indeed.

I doubt this Justice Department’s readiness to turn a prosecution into political leverage will stop with the Adams case. It will be interesting to see what happens in the fraud prosecution of Gautam Adani, a close ally of President Narendra Modi of India, in the Eastern District of New York, now that Mr. Trump and Mr. Modi have met. I fear the administration’s demand for absolute fealty will destroy the culture and morale of offices filled with people drawn to the job by a hatred of bullies and a desire to at least try to do the right thing, without fear or favor. I also see the administration’s intense focus on immigration cases, to the exclusion of corruption and white-collar cases of all sorts, turning the department into a protector of the privileged and scourge of the unfortunate.