In the context of the transnational rule-of-law crisis the world is experiencing, this chapter asks whether the institutional solutions typically embraced by contemporary Latin American constitutions make a difference in fighting contemporary patterns of rule-of-law violations, and what sort of difference they make. The chapter advances the preliminary hypothesis that Latin American last-wave constitutions make a positive difference. After recalling historic trends with regard to democracy and the rule of law in Latin America and providing an overview of the standard institutional tools contained in Latin American constitutions, it describes the patterns of rule-of-law undermining that dominate the current political scenario in Mexico. The chapter especially addresses attacks on the National Electoral Institute and the quest to weaken electoral reliability, and the militarization of public life and state functions. The analysis shows that the Mexican constitution is successfully used to resist these developments, but it also suggests that existing dynamics excessively rely on ex post reaction and the overcharge judiciary.