Partisan Joiners: Associational Membership and Political Polarization in the United States (1974–2004)


  • *Direct correspondence to Delia Baldassarri, Department of Sociology, Princeton University, 147 Wallace Hall, Princeton, NJ 08544 〈〉. The author thanks Peter Bearman, Antonio Chiesi, Mario Diani, Paul DiMaggio, Fabio Franchino, Andrew Gelman, Peter Hedström, Michael Hout, Art Stinchcombe, and Masanao Yajima for useful comments. Previous versions of this article were presented at Princeton, UC–Berkley, and the University of Milan. Financial support from the Princeton Institute for International and Regional Studies is gratefully acknowledged. The usual disclaimer does apply. The data used in this article are publicly available, while the R code to perform the analysis is available from the author upon request.


Objectives. Associational life may foster political integration or amplify division, depending on how individuals partition themselves into groups and whether their multiple affiliations embed them into concentric or cross-cutting social circles. Starting from this premise, I relate trends in associational membership to political partisanship, and ask if there is any evidence of increased political polarization in the associative patterns of Americans.

Methods. Using GSS data (1974–2004) on affiliations to 16 types of groups, I plot trends and run multilevel models to examine changes over time in the partisan allegiances of group members and patterns of overlapping memberships.

Results. The often-lamented decline in group membership affects primarily the category of single-group members and is limited to a few types of groups. The density of the network of overlapping memberships has remained stable over time and there are no real changes in the patterns of shared memberships between group types, nor do Republicans and Democrats differ in their patterns of preferential affiliation. Although political partisanship does not drive patterns of group affiliation, group members, especially those affiliated with multiple groups, are more radical in their partisan identification than nonmembers, and most types of groups have become politically more heterogeneous over time.

Conclusion. The puzzling finding that group types are not becoming more partisan, while group members are, leads to the hypothesis (to be tested in future research) that civil society polarization is occurring at the level of actual groups, and not group types.