Trump’s Justice Department doesn’t understand that four is less than five

There is literally no rule more basic to U.S. litigation than the rule of five. The Supreme Court has nine seats. It takes a majority to decide a case. A decision joined by five or more justices is a binding interpretation of the law that controls all other court decisions. An opinion dissenting from such a decision is just someone’s views.

And yet, a pair of briefs filed Wednesday evening by a team of anti-Obamacare lawyers — including one filed by the Trump Justice Dep...