The responsiveness of political parties to voters’ policy preferences is a core feature of democracies. A growing number of studies analyze this phenomenon, but key obstacles remain, such as the availability of reliable measures and the infrequency of these measures (election periods). As a consequence, the literature remains vague in theorizing and analyzing instances where the preferences of the median voter clash with those of the party electorate. By studying party responsiveness in a different setting, this paper advances the literature on these fronts: we focus on the Swiss political context, where the frequent use of direct democratic institutions enables us to evaluate the dynamic responsiveness of political parties with several observations per year for a large variety of topics. The paper uses a Bayesian item response theory model to operationalize the general ideological position of ballot proposals and uses them to evaluate parties’ responsiveness to the median voter and party voter. Our results confirm the most recent literature that political parties are responsive to their own electorates’ position shift but not the median voter. Furthermore, we show that, in situations where the signal from the general electorate and the party voters disagree, parties value the party voter more, thus giving even more weight to their partisan electorate. These findings have important implications for the study of party responsiveness.