Groups and the Party Coalitions: A Network Analysis of Overlapping Donor Lists

How are factions within the two major political parties related to each other? How tightly knit are the two political parties? Are there major structural differences between them? This paper examines the composition of the Democratic and Republican party coalitions by using social network analysis to analyze the contribution patterns of elite donors. I first identify all individual donors who gave over $200 to one of the two major political party committees in the 2003-2004 election cycle. I then trace the contributions that each of those donors made to the most partisan committees and ideological groups. I then convert this two-mode data to a dataset that shows the degree of overlap between each group’s donor pool, and conduct a series of exploratory analyses using network analysis techniques. These analyses show that both parties are similar in their degree of centralization, with the party committees being the most central actors in the network. For the Democrats, 527 organizations occupy central positions, whereas for the Republicans, Leadership PACs are most central. In neither party are there distinguishable interest group factions that are isolated from the rest of the party network.