In less than a month in power, President Trump’s political appointees have embarked on an unapologetic, strong-arm effort to impose their will on the Justice Department, seeking to justify their actions as the simple reversal of the “politicization” of federal law enforcement under their Biden-era predecessors.

The ferocious campaign, executed by Emil Bove III — Mr. Trump’s former criminal defense lawyer who is now the department’s acting No. 2 official — is playing out in public, in real time, through a series of moves that underscore Mr. Trump’s intention to bend the traditionally nonpartisan career staff in federal law enforcement to suit his ends.

That strategy has quickly precipitated a crisis that is an early test of how resilient the norms of the criminal justice system will prove to be against the pressures brought by a retribution-minded president and his appointees.

On Thursday, the interim U.S. attorney in Manhattan, Danielle R. Sassoon, resigned rather than sign off on Mr. Bove’s command to dismiss the corruption charges against Mayor Eric Adams of New York. Ms. Sassoon is no member of the liberal resistance: She clerked for the conservative Supreme Court justice Antonin Scalia, and had been appointed to her post by Mr. Trump’s team.

Dropping the charges, “for reasons having nothing to do with the strength of the case” went against the “duty to prosecute federal crimes without fear or favor,” she wrote in a letter to Mr. Bove explaining her decision.

Mr. Bove, rebuffed by Ms. Sassoon, tried a procedural end-around, asking officials in the department’s Washington headquarters to take over the case, then have someone on their staff sign the dismissal.