On the other hand, there are good reasons to think that this law-and-order focus is a significant mistake, that it over-reads the current moment of Baton Rouge, Dallas and Nice and will not be the right focus for the fall.

In the first place, it’s based on a falsehood. Crime rates have been falling almost without fail for 25 years. Murder rates have been rising just recently among gangs in certain cities, but America is much safer than it was a decade ago. In the first half of 2015, for example, the number of shootings in New York and Washington hit historic lows.

Trump dwells on illegal aliens killing our children. Between 2010 and 2014, only 121 people released from immigration custody later committed murder; that’s about 25 a year. Every death is a horror, but the number of police officers killed each year as a result of a crime is about 55, in a nation of over 320 million people. The number of police deaths decreased by 24 percent between 2005 and 2015.

The main anxieties in this country are economic and social, not about crime. Trump surged to the nomination on the back of his supposed business acumen, not because he’s a sheriff. By focusing so much on law and order, he leaves a hole a mile wide for Hillary Clinton. She’ll undoubtedly fixate at the Democratic convention in Philadelphia on economic pain. Trump could end up seeming strangely detached.

But if Trump is detached from the country, and uninterested in anything but himself, he’s also detached from his party. Trump is not really changing his party as much as dissolving it.

A normal party has an apparatus of professionals, who have been around for a while and who can get things done. But those people might as well not exist. This was the most shambolically mis-run convention in memory.