Associative theorists of political obligation argue that individuals are bound to the political society of which they are members and that membership itself is the primary ground of political obligation. Some critics claim that this argument fails in large part because any plausible associative account collapses into some non-associative theory of political obligation. This article rejects such claims, arguing that associativism is in fact a distinctive approach to political obligation. Specifically, it holds that the normative force of associativism is irreducible to either the voluntarism of consent or the universalism of natural duty theories of political obligation. Although there may be some similarities between associative accounts and these alternative theories, there are also important differences that mean the associative account cannot be assimilated without significant remainder to non-associative theories. Hence, associative accounts offer a genuinely distinctive approach to political obligation. However, whether they offer a better approach is not a question that this article addresses.