Political factions are rarely treated as normatively desirable entities in constitutional or international law. On the contrary, they are either regarded as forces that thwart the general welfare or as sources of chronic political instability. Thus, the conventional wisdom often focuses on how to deploy institutional or legal structures that minimize the influence of faction. By contrast, this Essay argues that the institutions of constitutional and international law that are forged by self-interested factions can create significant side benefits for the rest of the society. At bottom, such institutions are likely to be more durable and energetic than those created by disinterested or high-minded social designers. Thus, rather than focus on trying to curtail the influence of faction in shaping political institutions, it may make more sense to broaden the scope of such influence to be as inclusive as possible.