In this Paper we posit that both negative and anti-establishment political identities are crucial to explain the recent electoral successes of populist actors. While a negative political identity alludes to an emotional and rational repulsion towards one specific political party of a given country (e.g. PP or PSOE in the case of Spain), an anti-establishment political identity entails the rejection of all mainstream political parties as dishonest and corrupt (e.g. PP and PSOE in the case of Spain). Therefore, an anti-establishment political identity provides a fertile ground for populist sentiments and thus ultimately populist voting behavior. We test our theory for the case of Spain in an electoral context that saw the established two-party dominant system being seriously challenged by two new contenders: Ciudadanos (a non-populist party) and Podemos (a populist party). Using original survey data fielded in the week before the election in December 2015, we show that anti-establishment political entity and populist sentiments are indeed linked to vote choice for Podemos and interact with ideology in expected ways.
