He was a Radical Party leader, based on his outspoken opposition to the regime of Juan Domingo Perón. He was expelled from Congress by the Peronists and even jailed in 1950. In 1951 Balbin ran against Perón in the national presidential election with Arturo Frondizi as his running mate as vice president. The UCR was handily defeated by Perón.
In 1956, following the fall of Perón, the UCR split into two parties. Balbin headed the UCRP (Unión Cívica Radical del Pueblo), the Radicals of the People, and Frondizi formed the UCRI (Unión Cívica Radical Intransigente), the Intransigent Radicals. The split was caused by personality conflicts and policy differences. Balbin’s faction adamantly opposed both cooperation with the Pe- ronists and the opening up of the Argentine economy to foreign corporations, emphasized traditional individual freedoms, and strongly opposed corruption and dictatorship. Frondizi was more amenable to cooperation with the Peronists, and he and the UCRI. with the help of the Peronist votes, defeated Balbin and the UCRP in the 1958 presidential election. Frondizi was later ousted in a coup in 1962.
In 1963 the UCRP’s candidate Arturo Umberto Illia won the presidential election but was overthrown by a 1966 military coup. Balbin retained control of the party machinery for the following decade, and in 1973 he was twice named the UCR’s presidential candidate. In the first election ot that year he lost badly to the Peronist candidate Héctor Cámpora. getting only 21 percent of the vote, while in the second election he was defeated by Perón himselt.
During the period of military government after 1976, Balbin remained the dominant figure in the UCR until his death. He called for return to civilian government but was less prominent in denouncing human rights violations than were such younger party leaders as Raúl Ricardo Alfonsin Foulkes, who succeeded him as UCR leader.