Michigan v. EPA and the Erosion of Chevron Deference

The deference that courts grant agency statutory interpretation has long been a source of tension between the three branches of government. Within that tension lies vital issues concerning political accountability, technical expertise, and the methods courts use to deal with a massive modern administrative state that was unimaginable at the time that the Constitution was dr afted. When it was decided in 1984, Chevron U.S.A. v. Natural Resources Defense Council sought to alleviate that tension, leaving broad interpretative authority to executive agencies, so long as their interpretations did not conflict with c ongressional intent and were reasonable. Just over three decades later, there are signs that Chevron is buckling. In Michigan v. EPA , decided in the summer of 2015, the Supreme Court struck down a major regulation that set standards for emissions of mercury and other pollutants from power plants, on the grounds that the Environmental Protection Agency (EPA) had unreasonably interpreted the Clean Air Act (CAA or the Act). This holding represents a significant departure from the traditional application of Chevron , and a sign that the Court may be moving away from a deferential standard of review of agency statutory interpretation. This note analyzes Michigan and where it fits within the ever-evolving framework of the Court’s application of Chevron , and how the case could contribute to a continuing decline in the doctrine’s importance and applicability. Part II provides background information on the Chevron doctrine, and how the Court has historically deferred to agency statutory interpretation. Part III examines the facts of Michigan and the approaches that the Justices took on their reasoning, and Part IV analyzes these approaches and explains how Michigan fits into an ongoing trend away from Chevron ’s highly deferential standard. Finally, Part V explores the possible implications of the holding in Michigan , and how this decision could affect the regulatory process—and challenges to it—in years to come