An enduring and increasingly acute concern-in an age of polarized parties-is that people's partisan attachments distort preference formation at the expense of relevant information. For example, research suggests that a Democrat may support a policy proposed by Democrats, but oppose the same policy if proposed by Republicans. However, a related body of literature suggests that how people respond to information and form preferences is distorted by their prior issue attitudes. In neither instance is information even-handedly evaluated, rather, it is interpreted in light of partisanship or existing issue opinions. Both effects are well documented in isolation, but in most political scenarios individuals consider both partisanship and prior opinions-yet, these dynamics may or may not pull toward the same preference. Using nationally representative experiments focused on tax and education policies, I introduce and test a theory that isolates when: partisanship dominates preference formation, partisanship and issue opinions reinforce or offset each other, and issue attitudes trump partisanship. The findings make clear that the public does not blindly follow party elites. Depending on elite positions, the level of partisan polarization, and personal importance of issues, the public can be attentive to information and shirk the influence of party elites. The results have broad implications for political parties and citizen competence in contemporary democratic politics.