Presumptuous Preemtion: How Plain Meaning Trumped Congressional Intent in Engine Manufacturers Association v. South Coast Air Quality Management District

Abstract

After discovering that diesel exhaust generated by mobile sources caused 70% of the airborne cancer risk in California's South Coast Air Basin, the South Coast Air Quality Management District promulgated a set of rules designed to reduce the output of these toxic emissions. The rules imposed purchase restrictions on certain fleet owners that prevented them from purchasing a diesel powered vehicle if a clean-fueled alternative vehicle was commercially available. In Engine Manufacturers Ass'n v. South Coast Air Quality Management District, the Supreme Court held that such purchase restrictions were expressly preempted by the Clean Air Act. In contrast with the Court's traditional insistence that congressional intent is the critical inquiry in preemption cases, the majority based its decision solely on what it considered to be the plain-meaning of the text of the statute and abandoned the long-standing presumption against preemption. This Note scrutinizes the reasoning of the Court's opinion and finds its holding unsupported by either the text or the history of the Clean Air Act. It argues not just that the Court erred in finding the terms of the statute unambiguous, but that the plain-meaning approach to statutory interpretation, which presupposes a degree of verbal precision and stability our language has not attained, has no proper place in preemption analyses. Finally, as the decision has important implications for the future of federal preemption and the continued viability of local control, especially in the context of environmental law, this Note attempts to predict the circumstances under which the Court will fail to apply the presumption against preemption in the future.