A spokeswoman denied that the Justice Department was taking orders from the president in recommending the lower sentence, a claim Mr. Trump undermines every time he opens his mouth. On Tuesday, he announced that he has an “absolute right” to tell the Justice Department what to do.

No, in fact, he does not. The Constitution compels the president, among other things, to “take care that the laws be faithfully executed.” Since Mr. Trump has described that document as “like a foreign language,” we’ll take this opportunity to inform him that this clause does not give him the authority to run the Justice Department like a goon squad at one of his failed casinos.

Republicans in Congress tried once again to rationalize the president’s irrational behavior. Senator Marco Rubio said it was “not uncommon” for line prosecutors to be overruled by their superiors.

Actually it is quite uncommon, particularly when the original recommendations fall within the federal guidelines range. If there were any genuine concerns over the length of Mr. Stone’s recommended sentence, the department has well-established protocols for addressing those concerns in an orderly way.

In any ordinary Justice Department, a president publicly calling for leniency toward a close personal ally would set off alarm bells. But this, of course, is no ordinary Justice Department. An aspiring autocrat is only as powerful as his enablers, and Mr. Trump hit the jackpot in Mr. Barr, who is now taking control of all cases involving the president, including Mr. Stone’s conviction. He has also agreed to accept information from the president’s actual personal lawyer, Rudy Giuliani, who has been sniffing around Ukraine looking for dirt on Joe Biden and his son, Hunter — part of an effort, you may recall, that recently resulted in Mr. Trump’s impeachment.

Mr. Barr cautioned that he would be “very careful” with any information coming out of Ukraine. Mr. Trump, we can be confident, will not. In his world, the criminals are the victims, while the real crooks are those who devote their lives to the rule of law.

The departure of four respected prosecutors under these circumstances should worry all Americans. As Republicans in Congress abdicate their responsibility to act as a check on the executive and Mr. Trump packs the Justice Department with loyalists like Mr. Barr, the nonpolitical administration of justice depends all the more on career civil servants who have dedicated themselves to upholding the law, and not to helping a president abuse his office.