This article builds on V.O. Key's postulate that voters are not fools and that they function as an echo chamber reflecting the clarity of alternatives presented to them. We first propose a reassessment of Key's claim by examining whether and to what extent the impact of issue preferences on the vote choice depends on the clarity of parties' profile on these issues. Our empirical tests are based on data from the 2007 Swiss election study and cover three different issues that voters may use as decision-making criteria. Our results confirm that the clearer a party's profile on a given issue, the higher the impact of that issue on the vote for the party. Second, we offer a refinement of Key's argument by arguing that voters' political sophistication conditions the strength of issue voting. Empirical evidence supports this argument, but shows that the effect of political sophistication is curvilinear: sophistication exerts a stronger mediating role when a party has a moderately clear profile than when it has a low or high profile.