We have all gotten used to it, but if you take a step back, that Trump as president would attack his Cabinet officials via Twitter would have seemed one of the more lurid fears of his critics before he was elected. But here we are.

The ongoing spat with Sessions is another reason the administration gives off a sense of teetering on the edge of a crisis, not because of exogenous events (we’re experiencing peace and prosperity), but because of the ultimate endogenous factor — the president of the United States, without whom the administration wouldn’t exist in the first place.

If Trump were to fire Sessions, which seems unlikely, or to eventually push him over the edge into quitting, he probably wouldn’t be able to get another attorney general confirmed. Who would be acceptable both to Trump, who wants more personal loyalty, and to the Senate, which isn’t going to approve a crony? And what graybeard with independent credibility would sign up to serve?