This paper examines the motivation behind establishing judicial review in a new democracy. Using Tunisia as a case study, it explores how political actors successfully created a constitutional court with the power of judicial review following the collapse of the authoritarian Ben Ali regime. I argue that the diffuse nature of the Constituent Assembly, in addition to the activist character of Tunisian civil society, allowed for the emergence of a constitutional court with strong powers of judicial review. This argument builds on Thomas Ginsburg’s insurance and commitment theories, which posit that when a majority is in charge of drafting the constitution, it often chooses to include strong powers of judicial review. According to this logic, strong judicial review powers act as a type of insurance for the majority party; should it be deposed in the future, the party would still be protected by the constitutional court it established in the constitution-writing stage. I critique the limits of Ginsburg’s Commitment Theory and adapt it to include civil society. To prove causality, I use process tracing; I utilize both sequence and mechanisms to explain the relationship between diffuse political parties and an activist civil society with the establishment of a constitutional court and judicial review. To enhance my causal claim, I select another country for comparison that varies on the independent variables: Egypt. While Tunisia had a diffuse Constituent Assembly and an active civil society, Egypt’s Constituent Assembly was extremely homogeneous and its civil society was suppressed. In turn, Tunisia established very strong judicial review while Egypt did not.