Mick Mulvaney over the weekend said, regarding the Doral decision, that Trump “still considers himself in the hospitality business.” This is an innocent explanation in one sense: It doesn’t occur to Trump that he’s doing anything untoward in, say, wanting to host the G-7 at Doral because he just wants to show people a good time at what he, of course, considers one of the best golf resorts in the world. On the other hand, it’s quite damning — the president of the United States should be focused on one role and job at a time, which is obviously being president of the United States. That Trump has never absorbed this basic insight is one of the worst aspects of his presidency.