Abstract
This paper advances normative theorizing about political parties by highlighting concerns arising from recent empirical scholarship on marginal partisanship, affective polarization, and identity convergence. These phenomena challenge the ideal of healthy partisanship as characterized in recent democratic theory, and point toward a new theoretical agenda. I argue that democratic theorists' current focus on the virtues of mature partisanship has obscured essential questions about the scope of partisanship as an ideal and about processes of partisan socialization and mobilization.