Chief Justice John Roberts drives conservatives crazy with his habit of split-the-difference jurisprudence. But his final, short paragraph in one opinion today at least gave constitutionalists solid reasons for hope.

Roberts disappointed constitutionalists by refusing to overturn the doctrine known as “Auer deference,” via which courts defer to executive agencies’ interpretations of their own rules. He did signal, however, that he is quite open to re-examining a related doctrine called “Chevron deference,” via which courts defer to the agencies’ interpretation of statutory language passed by Congress.