Despite a growing interest in corruption, the topic has been absent from democratic theory. The reason is not a lack of normative issues, but rather missing links between the concepts of corruption and democracy. With few exceptions, political corruption has been conceived as departures by public officials from public rules, norms, and laws for the sake of private gain. Such a conception works well within bureaucratic contexts with well-defined offices, purposes, and norms of conduct. But it inadequately identifies corruption in political contexts, that is, the processes of contestation through which common purposes, norms, and rules are created. Corruption in a democracy, I argue, involves duplicitous violations of the democratic norm of inclusion. Such a conception encompasses the standard conception while complementing it with attention to the dynamics of inclusion and exclusion within democratic politics. By distinguishing the meanings of inclusion and exclusion within the many institutions, spheres, and associations that constitute contemporary democracies, I provide a democratic conception of corruption with a number of implications. The most important of these is that corruption in a democracy usually indicates a deficit of democracy.