Chief Justice Roberts, writing the opinion of the court, argued Chevron "defies the command of" the Administrative Procedure Act, which governs federal administrative agencies.

He said it "requires a court to ignore, not follow, 'the reading the court would have reached had it exercised its independent judgment as required by the APA.'"

Further, he said it "is misguided" because "agencies have no special competence in resolving statutory ambiguities. Courts do."

"In dissent, Justice Kagan says the conservative supermajority "disdains restraint, and grasps for power," making "a laughingstock" of stare decisis and producing "large-scale disruption" throughout the entire government. She is both furious and terrified."