Institutional Revolutionary Party
The Institutional Revolutionary Party (, PRI) is a Mexican political party founded in 1929 that held uninterrupted power in the country for 71 years from 1929 to 2000, first as the National Revolutionary Party (, PNR), then as the Party of the Mexican Revolution (, PRM), and finally renaming itself as the Institutional Revolutionary Party in 1946.
Party of the Democratic Revolution
The 1988 electoral fraud sparked a movement against the authoritarian rule of the PRI and towards a democracy. As an integral part of the movement towards democracy, the Party of the Democratic Revolution was formed as Mexico's only leftwing party. On May 5, 1989, Cárdenas declared the establishment of the PRD. Former PRI members who also helped found the PRD include: Cárdenas, Porfirio Muñoz Ledo, and Ifigenia Martínez y Hernández.