Mexican Revolution
The PRI, or Institutional Revolutionary Party is one of the major lasting legacies of the Mexican Revolution; its first iteration was the Partido Nacional Revolucionario founded in 1929 under Northern revolutionary general and president of Mexico (1924–1928) Plutarco Elías Calles, following the assassination of president-elect (and former president) Álvaro Obregón in 1928. The establishment of the party created an enduring structure that managed not only presidential succession but also groups with competing interests. Initially, Calles remained the power behind the presidency during a period known as the Maximato, but his hand-picked presidential candidate, Lázaro Cárdenas, won a power struggle with Calles, expelling him from the country. Cárdenas reorganized the party that Calles founded, creating formal sectors for interest groups, including one for the Mexican military. The reorganized party was named Party of the Mexican Revolution. In 1946, the party again changed its name to the Institutional Revolutionary Party. The party under its various names held the presidency uninterruptedly from 1929 to 2000, and again from 2012 to 2018 under President Enrique Peña Nieto.
Lázaro Cárdenas
The Partido de la Revolución Mexicana (PRM) came into being on March 30, 1938 after the party founded in 1929 by Calles, the Partido Nacional Revolucionario (PNR), was dissolved. Cárdenas's PRM was reorganized again in 1946 as the Institutional Revolutionary Party. Calles founded the PNR in the wake of President-elect Obregón's assassination in order to create some way for revolutionary leaders to maintain order and power. Calles could not be re-elected as president, but did hold power through the newly created party. Often called the “official party”, it “was created as a cartel to control localized political machines and interests.”