The U.S. Supreme Court in Loper Bright Enterprises v. Raimondo has unsettled modern foundations of administrative law by overturning its own decision of 40 years ago in Chevron U.S.A. v. Natural Resources Defense Council, 467 U.S. 837 (1984). Chevron deference, as the doctrine became known, required considerable and often abject deference to an agency's interpretation of a statute that Congress has tasked it with enforcing. Chevron deference is a two-step process that first asks whether the statutory provision in question is clear and unambiguous and, if not, then asks whether the agency's interpretation of the unclear statute is reasonable. In practice, the second step of Chevron is all but toothless; once the text of a statute has been deemed ambiguous, one can hardly find a case in which the court then determines that the agency interpretation of that ambiguous statute was "unreasonable," even if it is against the weight of analysis using the multitude of interpretive tools that courts otherwise employ to construe statutory text.

In Loper, the court now interprets the language of the federal Administrative Procedures Act as vesting the role of interpreting the language of statutes ultimately on the courts, which have traditionally exercised this function. "[A]gencies have no special competence in resolving statutory ambiguities. Courts do." In doing so, courts should use all the traditional tools of statutory construction, and not limit themselves to the single determinant of whether the agency interpretation is unreasonable. The court noted: "The very point of the traditional tools of statutory construction is to resolve statutory ambiguities. That is no less true when the ambiguity is about the scope of an agency's own power—perhaps the occasion on which abdication in favor of the agency is least appropriate." The Loper court will now require that federal courts resolve such ambiguities by exercising "independent legal judgment."