Judicial obligation to enforce the law is typically regarded as both unproblematic and important: unproblematic because there is little reason to doubt that judges have a general, if prima facie, obligation to enforce law, and important because the obligation gives judges significant reason to limit their concern in adjudication to applying the law. I challenge both of these assumptions and argue that norms of political legitimacy, which may be extra-legal, are irretrievably at the basis of responsible judicial reasoning.