Why did the Stone matter so clearly warrant resignation? The president has used Twitter to denounce and pressure department officials, senior administration lawyers and the Mueller team. When he did that to Attorney General Jeff Sessions, his deputy attorney general, Rod Rosenstein, and the special counsel Robert Mueller, they stuck it out. They must have thought that the best way to serve the rule of law was to hold off or humor the president, maintaining regular order as much as possible even as Mr. Trump raged that he could not fully control his department.

And there is a case to make for their choice. Mr. Sessions stood up to the president and adhered to his decision to recuse himself from the Russia investigation. Mr. Mueller was not fired and completed his investigation in the Russia matter.

But this time, the president got what he wanted. Mr. Trump attacked the department sentencing recommendation as an unacceptable “miscarriage of justice” that was “horrible and unfair.” And then the department did switch positions on the sentencing, criticizing its own prosecutors for failing to be “reasonable” in their recommendation to the court.

This, then, could be seen as the extreme case, whereas normally a lawyer might decide that “working from the inside” is the best, most responsible answer to the president’s behavior.

Still, if resignation had been seen earlier as viable, even necessary option, it’s possible that we would not have arrived at this point. Mr. Sessions could have resigned over the president’s public calls for him to ignore his recusal requirements or prosecute Hillary Clinton. If Mr. Mueller had resigned over the president’s attacks on him and refusal to sit for an interview, he might not have completed his report but he would have rendered a devastating and unequivocal judgment. And, without a report he felt compelled to rely on, Mr. Mueller might have felt himself more at liberty to testify in detail to Congress.