Polarizing Cues


  • Stephen P. Nicholson is Associate Professor of Political Science, School of Social Sciences, Humanities and Arts, University of California, Merced, 5200 North Lake Road, Merced, CA 95343 (snicholson@ucmerced.edu).

  • An earlier version of this article was presented at the 2009 Shaumbaugh Conference “Understanding the 2008 Presidential Election,” University of Iowa. I thank Kevin Arceneaux, Yarrow Dunham, Tom Hansford, Evan Heit, Marc Hetherington, Sunshine Hillygus, Simon Jackman, Kyle Mattes, Scott McClurg, Jennifer Nicholson, David Nixon, Caroline Tolbert, Jessica Trounstine, and John Zaller for helpful comments and suggestions.


People categorize themselves and others, creating ingroup and outgroup distinctions. In American politics, parties constitute the in- and outgroups, and party leaders hold sway in articulating party positions. A party leader's endorsement of a policy can be persuasive, inducing co-partisans to take the same position. In contrast, a party leader's endorsement may polarize opinion, inducing out-party identifiers to take a contrary position. Using survey experiments from the 2008 presidential election, I examine whether in- and out-party candidate cues—John McCain and Barack Obama—affected partisan opinion. The results indicate that in-party leader cues do not persuade but that out-party leader cues polarize. This finding holds in an experiment featuring President Bush in which his endorsement did not persuade Republicans but it polarized Democrats. Lastly, I compare the effect of party leader cues to party label cues. The results suggest that politicians, not parties, function as polarizing cues.