In the critically important area of preemption, the Supreme Court's approach to statutory interpretation differs from the approach it follows elsewhere. Whether in politically salient matters, like challenges to Arizona's immigration laws, or in more conventional cases, such as those in which state tort liability overlaps with federal regulation, the Court's preemption decisions reflect a highly purposive approach to reading statutes, most notably through the application of "obstacle preemption" analysis. Recently, however, Justice Thomas has objected to the Court's failure in preemption cases to respect its more textualist approach to issues of statutory interpretation, and he has urged that obstacle preemption be abandoned. Although three other justices have endorsed some aspects of Justice Thomas's approach, no dramatic shift in the Court's approach has yet occurred.
This Article examines recent preemption decisions and seeks to explain why textualist premises have so little grip in this domain. One might therefore view this Article as, in part, a case study of the feasibility of textualism. I argue that Congress lacks the capacity, foresight, and linguistic tools to be able adequately to specify in statutory text the proper resolution of the range of preemption issues that invariably arise under regulatory statutes of any complexity. Consequently, the task of fashioning a workable legal system that integrates state and federal law necessarily falls to courts (with assistance in some instances from federal administrative agencies). This Article concludes by examining recent challenges to the presumption against preemption that Professor Nelson posed and Justice Thomas endorsed. It criticizes the Nelson/Thomas understanding that the Supremacy Clause calls for rejection of the presumption against preemption and explains the significant role that that presumption continues to play.