Barfield v. Harris

“[C]onsiderable weight should be accorded to an executive department’s construction of a statutory scheme it is entrusted to administer....” | “If the intent of Congress is clear, that is the end of the matter; for the court, as well as the agency, must give effect to the unambiguously expressed intent of Congress.” | “The court need not conclude that the agency construction was the only one it permissibly could have adopted to uphold the construction, or even the reading the court would have reached if the question initially had arisen in a judicial proceeding.”