The Supreme Court severely undermined free speech on Monday. It erred by refusing to hear an appeal of a defamation suit filed by a controversial climate scientist against the conservative publication National Review.

At issue was whether courts should allow the suit to reach a jury or whether instead, the magazine should enjoy what Justice Samuel Alito called “the protection afforded to journalists and others who use harsh language in criticizing opposing advocacy on one of the most important public issues of the day.” Alito dissented eloquently from the court’s refusal to review the case. Alito was absolutely right.