He became a prominent Corrientes Province supporter of the leader of the reformist UCR, Hipólito Yrigoyen, at a time when local politics were dominated by the Autonomist and Liberal parties.

His 1918 UCR candidacy for the Corrientes governorship was defeated, and he joined the legal department of the Banco de la Nación Argentina (the country's largest bank).

This support helped lead to Quijano's August 4, 1945 appointment as Interior Minister, a powerful position in Argentina at the time for its oversight of law enforcement.

[2] As Vice President, Quijano earned plaudits for his negotiations with neighboring Brazil, resulting in a temporary reintroduction of the ABC Pact that had included the two nations and Chile, earlier in the 20th century.

His prospective replacement, First Lady Eva Perón, was in similarly poor health and, after she pleaded with him personally, he reluctantly agreed to join the Peronist ticket.