This article considers a referendum which was held in the Republic of Ireland in 2004 involving a proposal to qualify the existing universal constitutional entitlement to birthright citizenship. Existing analysis of this referendum reflects dominant trends in citizenship scholarship. It does so by framing the issue in terms of two opposing perspectives - one particularistic (exclusive) and one universalistic (inclusive) - and positing the question of the 'politics' of citizenship as a trade-off between these diverging models. This article argues, however, that Rob (R.B.J.) Walker's notion of the constituent subject of (sovereign) politics challenges this dualistic framework as the necessary starting point for discussions about citizenship. It does so by problematizing the premise upon which it is based which is the taken-for-granted autonomous existence of persons (individuals) who are understood to be connected to, but ultimately separate from, 'the state.' This article concludes with reflections on what an alternative framework for exploring citizenship (based specifically on a historicization of subjectivity in relation to sovereignty) might look like. It suggests that this provides us with a different starting point to the prevalent form of a timeless dialectic of inclusion and exclusion, particularism and universalism, polis and cosmopolis currently determined by the boundaries of the Irish state. © 2011 Taylor & Francis.