Following the Mexican Revolution, the coalition of generals leading the nation under the auspices of the jefe máximo Plutarco Elías Calles that eventually became the Institutional Revolutionary Party (PRI) sought to keep the often fractious labor movement under control, and did so by repressing leaders and movements outside the dominant party.
Under Cárdenas, the Confederation of Mexican Workers (CTM), an umbrella of PRI-affiliated unions, became the instrument of PRI domination of labor.
Following the resolution, Alemán appointed "loyal" leaders to the petroleum workers' and miners' unions.
Díaz de León gained control of the union by means of an interior coup supported by the CTM and President Alemán.
The attorney general's investigation led to Díaz de León's ouster from the union presidency, but he was restored by agents of the federal government, who arrested his rival Luis Gómez Z. Díaz de León proceeded to alter union bylaws to deny voting rights to the rank-and-file.