His stupid tweets have now resulted in the Russia probe. That will help opioid addicts in Ohio. This Thursday he may have launched a Republican civil war: The Freedom Caucus had better “get on the team, & fast. We must fight them, & the Dems, in 2018!” That will help promote harmony. His staff has failed to absorb the obvious fact that Mr. Trump was so outsized, colorful, and freakish a character that their primary job, and an easy one it was, was to be the opposite—sober, low-key, reassuring. Instead they seemed to compete with him for outlandishness.

Whatever your feelings and views, whatever was said behind closed doors, in the photo-op the president of the United States must shake the German chancellor’s hand. Not only because you are a gentleman, not only because it is your job to represent America with grace, but because a baseline requirement of your office is to show public respect for a great nation with which we have a history, part of that history constituting a jewel in the crown of 20th-century world diplomacy.

It amazes me that in his dealings with the health-care bill Mr. Trump revealed that he has no deep knowledge of who his base is, who his people are. I’ve never seen that in politics. But Mr. Trump’s supporters didn’t like the bill. If they had wanted a Republican president who deals only with the right, to produce a rightist bill, they would have chosen Ted Cruz. Instead they chose someone outside conservatism who backed big-ticket spending on infrastructure and opposed cutting entitlements, which suggested he’d be working with Democrats, too.