Justice John Paul Stevens isn’t helping the gun debate

Retired Justice John Paul Stevens argues in a New York Times op-ed published Tuesday morning that “a constitutional amendment to get rid of the Second Amendment would be simple and would do more to weaken the N.R.A.’s ability to stymie legislative debate and block constructive gun control legislation than any other available option.”

It’s a provocative claim, but it also raises serious questions about what planet Justice Stevens is living on. As University of Texas...