Last November at a celebratory dinner during the Federalist Society’s annual meeting in Washington, U.S. Supreme Court Justice Neil Gorsuch, the main speaker, made a vow. “Originalism has regained its place and textualism has triumphed and neither is going anywhere on my watch,” he declared.

Gorsuch exercised that pledge Monday, and he did so standing alone, in dissent, for the first time this term in an argued case. Not even the court’s most steadfast originalist, Justice Clarence Thomas, would join Gorsuch’s dissent in the court’s first contracts clause case in a generation.