Laborist Party (Mexico)
The PLM was founded by Luis Napoleón Morones, one of Mexico's main union leaders. The PLM functioned as the political branch of the Regional Confederation of Mexican Workers (CROM), the country's most powerful union. In the 1920s the PL was the most powerful party in Mexico. Presidents Álvaro Obregón (1920–1924) and Plutarco Elías Calles (1924–1928) were elected on a PL ticket and in 1922 the PL managed to defeat the Liberal Constitutionalist Party (PLC) in congressional elections, becoming largest party in the Congress of Mexico. Competition with rivalling parties, including the PLC, the National Cooperativist Party (PNC), the Mexican Communist Party (PCM), the National Agrarianist Party (PNA) and the National Anti-Reelectionist Party (PNA) was often violent, the government usually supporting the PL.
After the assassination of Obregón, who was recently elected, in 1928 the party's power started to decline. Morones was suspected to benefit from Obregón's death and lost support. In 1929, Calles founded the National Revolutionary Party (PNR), which was to became the 'official' party. The PL last participated in election in 1940, when it supported the rightwing candidate Juan Andreu.