Deliberative systems theorists argue that the aims of deliberative democracy must be accomplished at the level of political systems as a whole, not at the level of individual system components. Assessing the performance of a deliberative system, however, requires specification of its essential functions. Jane Mansbridge et al. identify three such functions—an epistemic function, an ethical function, and a democratic function. Deliberative systems theorists associate the democratic function almost exclusively with the demand for inclusiveness. But inclusiveness alone cannot explain the alleged democratic shortcomings of deliberative minipublics. Critics of minipublics implicitly appeal to other values—in particular, the value of popular sovereignty. This suggests that the democratic function is multidimensional in ways that have thus far gone unacknowledged by deliberative systems theorists. The explication and defence of the democratic function, in ways that go beyond inclusion, is therefore of critical importance to deliberative systems theory.