A Social Networks Analysis of Internal Party Cleavages in Presidential Nominations, 1972-2008∗

Presidential nomination politics has often revealed schisms within the party coalitions. But are these divisions long-standing or temporary? Do they reflect a chaotic party or a coordinating one? I use a dataset of more than 8000 presidential nomination endorsements from 1972 to 2008 to identify the network of support in the nominating party, as well as the key players in that dynamic. I then apply social networks analysis techniques, including exponential random graph models, to explain those networks. Analysis gives insight into who is important, what groups are stable, and what characteristics lead them to act together. ∗Paper presented at the University of Wisconsin, Madison, American Politics Workshop, November 16, 2009. I would like to thank Matt Grossman, Gregory Koger, Lorien Jasney, Seth Masket, Suzanne Robbins, Jennifer Victor, John Zaller and participants at seminars at the University of Michigan, the Political Networks Conference at Harvard University and the Political Methodology conference at Yale University for useful comments on earlier drafts of this project.