Signalling Political Constraints on Constitutional Review

Scholars of judicial politics have long recognised that courts exercising constitutional review of policy face an enforcement problem and carefully avoid placing excessive constraints on policy-makers. In this article, I offer a new perspective on how courts solve their enforcement problem. I develop a formal model, showing that policy-makers who risk paying a high price for pursuing policy at odds with existing constitutional jurisprudence signal a credible threat of non-compliance and induce courts to show self-restraint. The model explains a puzzling pattern in the German Federal Constitutional Court's exercise of constitutional review. The German court shows self-restraint in its review of policy when policy-makers had ignored constitutional concerns voiced by their own political allies and hence risked rifts within the governing majority. Empirical evidence is provided based on novel data covering the German Federal Constitutional Court’s decisions on the constitutionality of federal laws from 1983 to 2017.