The Supreme Court’s announcement that it will take up gay marriage is more than a chance for the justices to recognize the emerging national consensus in support of gay rights. It is a chance for them to overrule the medieval views of Antonin Scalia. As if in response to the court’s announcement, the acid-tongued justice visited Princeton University late Monday and reiterated his opinion, expressed in a 2003 dissent, that a law banning sodomy is on par with laws forbidding bestiality or murder. “If we cannot have moral feelings against homosexuality, can we have it against murder? Can we have it against these other things?” Scalia said when a gay undergraduate pressed him on his views in support of anti-sodomy laws. He defended his noxious comparison: “I don’t think it’s necessary, but I think it’s effective.” “I’m surprised you weren’t persuaded,” he told the gay student of his reductio ad absurdum comparison. Scalia is right: His comparison is unnecessary. And he shouldn’t be surprised that Americans — including his colleagues on the court — are not persuaded. The court’s decision to take up a pair of gay-marriage cases is almost certainly good news for gay rights and almost certainly bad news for Scalia’s defense of discrimination. Chief Justice John Roberts didn’t let his court stand in the way of immigration and Obamacare, and he surely doesn’t want to be responsible for a modern-day Plessy v. Ferguson that stands against the fast-emerging majority in support of gay rights.