Democracy is facing may challenges around the world, from the erosion of long-held democratic norms in mature democracies like the United States, to renewed party system upheaval in Latin America and Eastern Europe, to the full-blown autocratic reversal in countries like Turkey or Thailand. This project studies how the obstacles that parties face in controlling their politicians interact with electoral rules, contextual conditions, and voter pressures to produce two phenomena that contribute to the erosion of democracy. This project develops general theoretical arguments, collects data on parties and politicians from multiple countries, proposes new strategies to measure party system instability, politicians’ performance, and candidates’ charisma, and summarizes the findings in general policy recommendations. In contributing to the understanding of the causes behind democratic backsliding, the project will identify policies and institutional arrangements that are most conducive to stable political parties and healthy democracies, two key components of national prosperity and international peace.<br/><br/>The research program integrates three key components: theory development, empirical analysis and methodological innovation. The project develops a series of formal theoretical models that examine the understudied strategic interactions between political parties as longer-lived entities and their shorter-sighted individual candidates, under the premise that these interactions can help explain a variety of forms of democratic disruption. The project develops new methodologies to capture hard-to-measure concepts of politician charisma, incumbent performance, and party strength. Using a series of quasi-experimental approaches and natural experiments, a rich set of novel empirical implications derived from the formal models are tested with data from multiple countries. The analyses both validate the theories and produce systematic empirical evidence to inform scholarly and policy debates.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.