He was elected to the Chamber of Deputies (1945–48). In 1956 he helped to found the moderate Popular Action Party and in 1963 was elected President with the support of both Popular Action and Christian Democrats in opposition to Haya de la Torre, the candidate for APRA (Alianja Popular Revolucionaria Americana). His first term of office (1963–68) is remembered for its social, educational, and land reforms, as well as for industrial development and the construction of a vast highway system across the Andes. He was a strong supporter of the US Alliance for Progress programme, but his economic policies resulted in high inflation. He was deposed by the army and fled to the USA. He returned briefly to Peru in 1970, but was deported. He returned again in 1976 and was again President (1980–85). During his second term inflation grew worse and he was unable to counter the terrorist activities of the Sendero Luminoso (the Shining Path organization).