Who’s at the Party? Group Sentiments, Knowledge, and Partisan Identity

In studying US partisanship, scholars often invoke a groups approach, wherein individuals’ group memberships affect their identification with the Democratic and Republican Parties. While this literature implies that partisanship stems from citizens’ sentiments toward the groups that constitute the parties’ membership, this particular proposition has not been thoroughly investigated. We, in turn, propose a group sentiments model of partisanship—a subtheory of the groups approach—wherein citizens harbor feelings toward many social groups and have reasonably accurate knowledge about how such groups align with the parties. When these factors are combined, the direction and strength of citizens’ partisanship are altered. Using cross-sectional and experimental data, we show that citizens’ sentiments toward politically aligned groups shape their partisanship irrespective of their own group memberships, revealing the importance of sentiments toward social in-groups and out-groups. Thus, apart from containing “people like me,” citizens also care about which party contains “people I like.”