Can the demos be uncoupled from the ethnos? Can there be a democratic politics of state‐boundaries, or are borders a condition of the possibility of democratic politics rather than a possible subject for those politics? The author argues for the decoupling strategy and affirms the possibility of a democratic politics about borders, anchoring the discussion in the politics of Northern Ireland. The argument turns on the analysis of public reasoning. It is argued first that culturalist accounts of self‐determination are misconceived and that political institutions, and not cultural identity, make collective self‐determination possible. Second, that the demos is constituted by acts of mutual recognition required by the practice of public reasoning, and that this practice cannot be confined with state‐boundaries. Taken together this allows us to conceive of the unity of a people as constituted by practices of public reason, given effect by institutions whose configuration is never finally fixed.