My key question is whether the collective right to self-determination justifies a right on the part of liberal democracies to exclude outsiders from entering and settling within their territorial jurisdiction, from accessing citizenship or from participating in the formulation of their ‘internal’ decisions or policies. I approach the research through critically analysing six different accounts of the practice and value of democratic self-determination, which can be categorised as: liberal nationalist, identity liberal, liberal communitarian, multicultural/republican, cosmopolitan/discourse theory and agonistic. I argue that although democracy does not and cannot logically call for the extension of participatory membership to all those affected or coerced by the decisions of a state, self-determination is compatible with porous boundaries demarcating social membership and citizenship. The position I advance recognises the importance of clearly demarcated jurisdictional boundaries for facilitating democratic self-determination, but holds that the existence of those borders, and the value and practice of self-determination, which they protect, are compatible with open access to social membership and citizenship. In contrast to what has become a prevalent line of thinking with regard to the politics of membership in liberal-democracies, I argue that the value of free movement championed by liberalism is compatible with the value of self-determination championed by democrats. If valid, the upshot of my argument is that liberal-democrats should support the right to self-determination as non-interference for distinct political communities, but not the self-determination of their social membership and citizenship policies.