Radical democracy is usually fleeting. What are the possibilities for institutionalising it? If we want to understand them, we have to look carefully at the institutions and practices of local government and distance ourselves from the ideal of the nation-state, focusing instead on the possibilities of the open city. In that context, this article refers back to the work of Hannah Arendt and Robert Dahl, considering it in light of more recent contributions from Nancy Rosenblum, Andy Merrifield, Jacques Ranciere, and others.