How Public Opinion Constrains the U.S. Supreme Court


  • Christopher J. Casillas is a Ph.D. Candidate in the Department of Government, Cornell University, 214 White Hall, Ithaca, NY 14853-7901 ( Peter K. Enns is Assistant Professor in the Department of Government, Cornell University, 214 White Hall, Ithaca, NY 14853-7901 ( Patrick C. Wohlfarth is Post-Doctoral Fellow in the Department of Political Science, Washington University in St. Louis, Campus Box 1063, One Brookings Drive, St. Louis, MO 63130-4899 (

A previous version of this article was presented at the 2008 annual meeting of the American Political Science Association, Boston, MA, the University of North Carolina's American Politics Research Group, and Cornell University's Graduate Colloquium. Wohlfarth appreciates research support from a University of North Carolina Thomas M. Uhlman Research Fellowship and the Duke–UNC American Politics Research Group. We also thank Nate Kelly for sharing his Policy Liberalism data, Jim Stimson for providing Policy Mood by Supreme Court term, and Dawn Chutkow, Micheal Giles, Chris Faricy, Krista Hlopak, Timothy Johnson, Kevin McGuire, William Mishler, Jamie Monogan, Elliot Slotnick, Jim Stimson, and Georg Vanberg for helpful comments. Data needed to replicate the analyses presented in this article can be found at


Although scholars increasingly acknowledge a contemporaneous relationship between public opinion and Supreme Court decisions, debate continues as to why this relationship exists. Does public opinion directly influence decisions or do justices simply respond to the same social forces that simultaneously shape the public mood? To answer this question, we first develop a strategy to control for the justices' attitudinal change that stems from the social forces that influence public opinion. We then propose a theoretical argument that predicts strategic justices should be mindful of public opinion even in cases when the public is unlikely to be aware of the Court's activities. The results suggest that the influence of public opinion on Supreme Court decisions is real, substantively important, and most pronounced in nonsalient cases.