Want to stop these riots? Reform the police.

Every Fourth of July when I was a boy, the Jaycees sponsored a carnival at our local park, followed by a concert from the town’s volunteer band and a fireworks show. The water-balloon toss and the cotton candy machine were delightful, I suppose, but the attraction that galvanized every boy at the fair was the chance to lay down two bucks for the chance to swing a sledgehammer at an old car.

This was big money in those days. An hour and a half mowing and trimming a neighbor’s lawn...