The conventional wisdom that parliamentary elections are now, more than at any time in the past, determined by voters' assessments of party leaders has been fiercely contested by comparative electoral research. To overcome the obvious mismatch between customary expectations about the role of party leaders and the conclusions drawn by scholarly research in the field, this book provides an innovative framework for the study of voting behavior in light of the ongoing personalization of politics. Through analysis of election study data from Britain, Germany and the Netherlands, this book highlights the progressive inability of social-psychological models of voting to account for individuals' choices. Throughout the last four decades, voters' attitudes towards party leaders have apparently become a crucial determinant of their feelings of affinity with certain parties. Once the role of leaders as drivers of partisanship is taken into account, their electoral effect emerges as a force that can – more often than not – make the difference between victory and defeat.