In an easy-to-overlook opinion on Thursday, U.S. Supreme Court Justice Anthony Kennedy sharply criticized the Chevron doctrine, raising questions about the future of judicial deference to federal agencies, and adding to the buzz in Washington about whether he will stay or leave the court.

His three-page concurrence in Pereira v. United States chastised circuit court judges for being too quick to bow to agency interpretation of statutes, accusing them of using “cursory analysis” instead of the kind of deeper review of the meaning of laws that the judiciary traditionally undertakes.