You don’t need to take my word on this point. Trump himself says it all the time—and loudly. He announces at every turn that he thinks the attorney general’s job is to protect him from the Russia probe and that he wants law enforcement to focus on Clinton. Rosenstein is only on Trump’s radar screen at all because the investigation of potential ties between associates of the Trump campaign and Russia required the attorney general’s recusal, a matter about which Trump also serially complains. The president’s attitude toward federal law enforcement is not just corrupt. It is openly and flamboyantly corrupt. He wants the FBI and the Justice Department to be at his beck and call. He wants them to be expressions of his power and interests.

That is a notion of federal law enforcement that this country turned decisively away from over a long period of time. The notion of law enforcement as professional, not political, began developing as an aspiration and an ethos even while in practice the FBI was the personal feifdom of J. Edgar Hoover. The modern norms of apolitical conduct and independence on investigative matters, which crystalized in the reforms that followed Watergate and the civil-rights era abuses, reflect not merely the shock of those abuses but decades of learned experience about law enforcement professionalism and how to do investigations well under a rule of law system. The question Trump is posing is whether we want to go back to a more primitive vision of the relationship between the president and the civilians with the power to lock people up.