Constitutional reasoning under diverse institutional designs generates different policy outcomes. In this article, I operationalize constitutional reasoning as argumentative and conceptual diversity in 15 jurisdictions of Latin America and the Caribbean. Each jurisdiction comprises information on the reasoning employed by the national courts over time (N=640). To compute landmark cases into argumentative and conceptual diversity, I consider items developed by the CONREASON project, as well as my own variables. Using cluster analysis, I group the 15 jurisdictions into two subsets contingent on the reasoning of judges over landmark cases. While the first cluster associates with democracies and high levels of institutionalization, the second displays radical leadership, hybrid regimes, and political instability. Relating argumentative and conceptual diversity with the overall quality of the constitutional reasoning, I report a substantial difference between the identified groups.