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 party was founded by smaller left-wing parties such as the Mexican Communist Party (PCM, "Mexican Communist Party"), Unified Socialist Party of Mexico (PSUM, "Unified Socialist Party of Mexico"), Socialist Mexican Party (PMS, "Socialist Mexican Party") and Mexican Workers' Party (PMT, "Mexican Workers' Party"). The PMS donated its registration with the Federal Electoral Commission (CFE) to enable the new party to be established.