Despite their importance to one another, the current literatures on political parties and normative democratic theory continue to develop largely in mutual isolation. Empirical studies of contemporary political parties and party systems tend to have little to say about the meanings and possibilities of democracy, and therefore also about the varied potential roles of political parties within it. Meanwhile, contemporary democratic theorists quietly sidestep the issue of whether political parties perform a legitimate function in democracies. This lack of mutual engagement is regrettable, in particular given the pervasive erosion of popular support and legitimacy of political parties as representative institutions. In this article we explore the key reasons for democratic theorists and scholars of political parties so rarely taking on each others' core concerns, and we outline the key ways in which this mutual disengagement is mutually impoverishing. We will also suggest ways forward, by pinpointing and illustrating potentially productive areas of engagement which might serve to deepen our understanding of democracy's present and its possible futures.Ingrid van Biezen is Reader in Comparative Politics at the University of Birmingham, UK (firstname.lastname@example.org). Michael Saward is Professor of Politics at the Open University, UK (email@example.com). The authors are grateful to Richard S. Katz and Jeremy Jennings and two anonymous reviewers for their insightful comments and suggestions. In developing our arguments, we also benefited from conversations with Robert Dahl, Russell Dalton, Ian Shapiro, workshop participants at the ECPR Joint Sessions, and graduate students at Yale University. Part of this research was supported by the British Academy (research grant SG 38612).