ABSTRACT
The most searching analysis of the development of the Partido Revolucionario Institucional is contained in an article by the Mexican sociologist Jose Luis Reyna. In writing about Mexican political developments of the 1920s, Reyna states; These indicators (economic growth, urbanization, industrialization, increased communication) taken together allow one to assume the validity of the hypothesis that, in effect, there was a certain economic dynamism in the decade. The period from the beginning of Plutarco Calles' presidential term in 1924 to the end of the Maximato in 1934 was one first of shared power with Alvaro Obregón and later of almost total power, exerted behind the scenes, by Calles alone. Calles was a politician and a survivor. He was also a person who, once he found politics, enjoyed and understood the uses of political power. Although political parties existed in Mexico during the 1920s, "almost all the States of the Republic were governed by caudillos and regional caciques.
