Múgica participated in the . For his positions and his debates with other delegates, he was always remembered as one of the best delegates and fundamental ideologists of the Mexican Revolution. He worked on part of the constitution concerning matters of religion, politics, economics and education. His ideology would be embodied in Articles 3, 27, and 123 of the Constitution of the United Mexican States. Mugica was made Governor of Michoacán briefly from 1920 to 1921. On 1 December 1934, Lázaro Cárdenas became the president of Mexico and named Múgica as the Secretary of the National Economy. He immediately made himself identifiable as one of the most "Cardenista" cabinet members, compared to those loyal to Plutarco Elías Calles. Cárdenas had begun to de-establish the "Maximato" by which Elías Calles had exercised command over every president since he left office in 1928. Múgica, a great ally of Cárdenas, helped in breaking the Maximato by creating a crisis in mid-June 1935 by releasing anti-labor statements made by Calles. The unions began strong protests against the figure of "Jefe Máximo" (Calles); they were immediately exploited to rid his influence on the government to seek and obtain the resignation of his entire cabinet and oust all Callistas, including Calles's son, the Secretary of Communications and Public Works. Cardenas then appointed Múgica to that post. With elections due to be held in 1940, Múgica was a natural successor to Cárdenas by being a strong leftist and believed in many of Cádernas's major reforms. Múgica was considered as a candidate for the presidency in 1939, but Cárdenas opted for General Manuel Avila Camacho, a moderate. Múgica was perceived as much more radical than Cárdenas. His supporters saw him as the great consolidator of the social work begun by Cárdenas, but his opponents saw him as a great danger that would make Mexico a copy of the Soviet Union. Múgica withdrew his candidacy and supported Avila Camacho. By 1939, the popularity of Cardenas had fallen seriously. Two figures on the right were arising to challenge the Cárdenas legacy: Joaquín Amaro and Juan Andrew Almazán. Cárdenas then realized that the candidacy of Múgica might not be well received by the country or internationally and that he needed a centrist candidate who was much less radical, could unify the divided population, and above all counter the rising popularity of Almazán.