Asymmetrical Polarization Within Members of the US Congress: A New Outlook

Abstract This paper investigates asymmetrical polarization in the United States House of Representatives, addressing the claim that the Republican Party has shifted further to the right than the Democratic Party has shifted to the left since the 1980s. While prior research has attributed this asymmetry to voter behavior, campaign finance, or elite organization, these factors are typically analyzed in isolation. This study reconceptualizes asymmetrical polarization as a networked and configurational outcome produced by the interaction of electoral, financial, and organizational ties. Methodologically, the paper integrates Social Network Analysis (SNA) and Discourse Network Analysis (DNA) to map ideological positions and relational structures among voters, donors, political organizations, and members of Congress. This approach goes beyond the DW-NOMINATE scoring system to account for various forms of political behavior. Donor and organizational ideologies are linked to candidates through campaign finance and endorsement networks. Voter attitudes and ideological orientations are assessed using American National Election Studies (ANES) data in an attempt to map out the primary electorates. To account for causal complexity, the study incorporates Qualitative Comparative Analysis (QCA) as a configurational framework. QCA is employed to identify combinations of network conditions—such as dense in-party elite ties, ideologically homogeneous donor clusters, weak cross-party brokerage, and ideologically motivated primary electorates—twhich are necessary for heightened polarization. This approach enables systematic comparison across parties and election cycles while avoiding linear, single-factor explanations. Preliminary findings suggest that Republican polarization is associated with a distinct network configuration characterized by high donor–elite ideological alignment, strong insurgent in-party clustering, and limited cross-party brokerage, whereas Democratic polarization follows more fragmented and conditional pathways. By foregrounding networks and configurations, the paper contributes to political network research by demonstrating how asymmetric polarization emerges from structurally different relational environments across parties.