This paper develops a comparative theory of judicial role that focuses on broad differences in political context, and particularly in party systems, across countries. The author uses a case study of the Colombian Constitutional Court (supplemented by briefer studies of the Hungarian and South African Constitutional Courts) to demonstrate how differences in political institutions should impact judicial role. Because Colombian parties are unstable and poorly tied to civil society, the Colombian Congress has difficulty initiating policy, monitoring the enforcement of policy, and checking presidential power. The Court has responded by taking many of these functions into its own hands. The author argues that the Court’s actions are sensible given Colombia’s institutional context, even though existing theories of judicial role would find this kind of legislative-substitution inappropriate. Existing theory’s focus on the anti-democratic nature of judicial action assumes a robust constitutional culture outside the courts and a legislature which does a decent job representing popular will – both assumptions tend to be false in newer democracies. Thus, the author concludes that comparative public law scholars must be attentive to political context in order to build tools suitable for evaluating the work of courts around the world.