American Political Science Review

Research Article

How Elite Partisan Polarization Affects Public Opinion Formation


a1 Northwestern University

a2 Stanford University

a3 Aarhus University


Competition is a defining element of democracy. One of the most noteworthy events over the last quarter-century in U.S. politics is the change in the nature of elite party competition: The parties have become increasingly polarized. Scholars and pundits actively debate how these elite patterns influence polarization among the public (e.g., have citizens also become more ideologically polarized?). Yet, few have addressed what we see as perhaps more fundamental questions: Has elite polarization altered the way citizens arrive at their policy opinions in the first place and, if so, in what ways? We address these questions with a theory and two survey experiments (on the issues of drilling and immigration). We find stark evidence that polarized environments fundamentally change how citizens make decisions. Specifically, polarization intensifies the impact of party endorsements on opinions, decreases the impact of substantive information and, perhaps ironically, stimulates greater confidence in those—less substantively grounded—opinions. We discuss the implications for public opinion formation and the nature of democratic competition.


c1 James N. Druckman is Payson S. Wild Professor, Department of Political Science, Northwestern University, Scott Hall, 601 University Place, Evanston, IL 60208 (

c2 Erik Peterson is a graduate student, Department of Political Science, Stanford University, Encina Hall West, 616 Serra Street, Stanford, CA 94305 (

c3 Rune Slothuus is Associate Professor, Department of Political Science, Aarhus University, Bartholins Alle 7, 8000 Aarhus C, Denmark (


  We thank Laurel Harbridge, Gabe Lenz, Matt Levendusky, Kerry O'Brien, Josh Robison, and seminar participants at Aarhus University for their helpful comments. We thank Allie Fredendall for research assistance. We also thank the Northwestern Office of Undergraduate Studies and the Danish Social Science Research Council (grant 275-07-0179) for financial support.