Some of the main proponents of constitutional economics consider this spin-off from public choice to be a research program, following Lakatos. In this paper I intend to show how constitutional economics can avoid becoming a degenerating program by focusing on its normative dimension. More specifically, I argue that the lessons of models developed within this research program can, and should be applied to political philosophy. However, this instance of epistemic imperialism is bound to have a significant effect on the auxiliary assumptions of constitutional economics, which will have to elaborate new hypotheses in order to avoid some of the counterintuitive implications to which it leads under its current positive heuristic. Throughout the paper, I focus mainly on the Leviathan model of government growth put forward by Brennan and Buchanan.