By every measurement, the recent Supreme Court decision in June Medical v. Russo, striking down a Louisiana law requiring that abortionists have hospital admitting privileges within a 30-mile radius of their facilities, was thin stuff. The margin was 5-4, and the deciding vote was provided by Chief Justice John Roberts. He had not only joined the dissent in a very similar case out of Texas four years earlier, but he went out of his way in this case to state that the previous dissent still represents his point of view.

So why the abrupt change of mind? Because the court majority, acting like a legislature, analyzed issues such as traveling distance to facilities and the proper assessment of physician skills and concluded that the district court had been justified in striking down the law despite its benefits to women’s health, which the Louisiana legislature had explicitly sought to achieve in enacting it.