The decline of deference: is the Supreme Court pruning back the Chevron doctrine?

Judicial deference to agency interpretations of ambiguous statutory terms -- a doctrine established in Chevron USA Inc v. Natural Resources Defense Council Inc, 467 U.S. 837 (1984) -- is one of the fundamental underpinnings of the modern administrative state. It has been particularly critical to the development of environmental regulations. Chevron deference has allowed Congress to paint its environmental goals in broad terms, in statutes like the Clean Air Act and the Clean Water Act, while leaving to the US Environmental Protection Agency the task of both determining what precisely Congress intended in those statutes and how exactly to achieve what the agency perceives to have been Congress's goals. Recent Supreme Court decisions suggest that a number of the Justices are concerned about -- and, in the case of Justice Thomas, openly hostile to -- Chevron deference. Under traditional Chevron analysis, where the statutory language is clear after applying regular rules of statutory construction, that language governs.