This book analyzes the transformation of the Mexican political system during the last four decades, focusing on its presidential elections. As the country has shifted away from an authoritarian political system, ruled by a hegemonic party, it has become a more moderate, pluralistic society, marked by electoral competition between contestant parties. Using a mixed methodology, including historical and statistical analysis, the author argues that the fight for clean and fair elections in Mexico has a long history of contestation and conflict, entailing at once movements towards democracy yet also processes of de-democratization.'