Do senators respond to the preferences of their state's median voter or only to the preferences of their co-partisans? We develop a method for estimating state-level public opinion broken down by partisanship so that we can distinguish between general and partisan responsiveness. We use these estimates to study responsiveness in the context of Senate confirmation votes on Supreme Court nominees. We find that senators more heavily weight their partisan base when casting such roll call votes. Indeed, when their state median voter and party median voter disagree, senators strongly favor the latter. This has significant implications for the study of legislative responsiveness and the role of public opinion in shaping the members of the nation's highest court. The methodological approach we develop allows more nuanced analyses of public opinion and its effects, as well as more finely grained studies of legislative behavior and policy-making.