Scholars are fascinated by courts that challenge constitutional amendments. However, scholars have given little attention to judges questioning the product of the original constituent power. Some argue that constitutions can be unconstitutional, but more work needs to be done to understand the role of judges. I develop a theoretical framework and explore examples from Latin America (i.e., Bolivia, Chile, Colombia, Ecuador, and Perú). The framework distinguishes three types of judicial challenges: the one against a constitutional amendment (Type 1), the one against a provision included in the original constitution (Type 2), and the one against a constitution (Type 3). While Type 1 challenges the constituted power, Type 2 challenges the original constituent power, and Type 3 recognizes the overall legitimacy of that original power while questioning part of the constitution. Type 1 protects the status quo, while Types 2 and 3 could trigger (or help to advance) a constitutional reform.