Who Deviates from the Party Line? A Comparative Analysis of the Policy Preferences of Candidates

While research on party politics has long been dominated by the unitary actor assumption, recent studies have shown how policy preferences of politicians differ within parties (Carroll and Kubo forthcoming, Steiner and Mader forthcoming). Building on this work on preference heterogeneity at the level of parties, we study the variation of party elites’ policy preferences at the level of individual candidates by asking who deviates from the party line. We are specifically interested in how socialization into and loyalty to the party affect how well candidates’ issue attitudes align with their party’s policy positions, and how these features interact with party characteristics. Empirically, we merge data from the CCS with data on party positions from the CHES and measures of party characteristics from the DALP dataset. Combining information on issue attitudes of candidates with party positions as perceived by experts, we construct measures of deviations from the party line for several policy dimensions (economic dimension, socio-cultural dimension, European integration, left-right position). We analyze these data via multilevel methods, modelling candidates as nested in parties in order to consider both individual-level and party-level determinants of deviant preferences as well as their interaction. Our study complements existing work that studied how politicians’ behavior—particularly with regard to voting in parliament—reflects adherence to the party line, but neglected direct attitudinal measures of politicians’ policy preferences. Distinguishing between cohesive behavior and aligned preferences helps to elucidate the relevance of different “pathways to party unity” (Andeweg/Thomassen 2011).