Democracy is not only a form of government. It is also the moral aspiration for a society of self-governing political equals who disagree about politics. Citizens are called on to be active democratic participants, but they must also acknowledge one another's political equality. Democracy thus involves an ethic of civility among opposed citizens. Upholding this ethic is more difficult than it may look. When the political stakes are high, the opposition seems to us to be advocating injustice. Sustaining Democracy poses the question: why should we uphold democratic relations with those whose politics we despise?