He became active in the Radical Civic Union and was elected to the Argentine National Congress in 1920. He served as minister of public works from 1925 to 1928. He supported the revolution of 1930 and served as treasury minister from 1935 to 1937.

In the presidential elections of 1937, he was the official government candidate and won, though the opposition accused him of participating in fraud, as irregularities were widespread. Ortiz never denied those charges but once he took office he tried to make Argentine politics more open and truly democratic. Sadly, soon after becoming president, Ortiz became seriously ill with diabetes and in August 1940, he gave up his powers to vice-president Ramón Castillo. He was pro-Ally but because of opposition in the army, he did not declare war on the Axis. He resigned a few days before his death.