Acceso usuarios
Party politics and electoral research generally assume that party members are loyal voters. Thisarticle rst assesses the empirical basis for this assumption before providing individual-level explanations fordefection. It combines prominent theories from party politics and electoral behaviour research and arguesthat internal disagreement and external pressure can each bring about disloyal voting. The hypotheses aremotivated with multi-country European survey data and tested on two sets of party-level national surveys.The results show, rst, that, on average, 8 per cent of European party members cast a defecting vote inthe last election, and second, that dissatisfaction with the leadership is the strongest predictor of defection.Additionally, internal ideological disagreement is associated with higher probabilities of defection, whereasthe effects of pull factors in the form of contentious policies are rather limited. These ndings emphasise theimportance of testing scientic assumptions and the potential signicance of party leadership contests.
