Do popular party leaders increase the vote share of their political party? The individual-level relationship between the popularity of party leaders and reported vote choice in parliamentary elections has been well established by existing survey research, however, whether a greater popularity of party leaders actually translates into higher party vote shares has received no systematic attention. In addition, the electoral consequences of affective voter polarization over party leader images have so far not been theorized sufficiently. I purport that polarizing party leaders have a greater positive effect on their party's vote share compared to universally popular leaders, because of their greater mobilization potential. This paper examines the relationship between leader popularity and changes in party vote share using cross-national survey and administrative data on parliamentary elections. The results enhance our understanding of polarization and the personalization of politics by identifying potential micro ecological fallacies in existing research and have important implications for the selection of party leaders.