In September 1955, Aramburu participated in a military coup called the "Revolución Libertadora". He led the hardliners and assumed the Presidency of Argentina himself, on November 13, 1955, after the resignation of moderate General Eduardo Lonardi. Admiral Isaac Rojas, was appointed vice-president. The Revolución Libertadora which overthrew Juan Domingo Perón was triggered in part by his actions towards the press, as well as the imprisonment of opposition leaders and economic instability. For example, Perón incited his followers to wreck the offices and printing presses of newspapers who criticized him and he jailed the leader of the opposition, Ricardo Balbin, of the Radical Civic Union party. The military Revolución Libertadora against Perón for these actions led to three years of military rule under Aramburu, who allowed elections to be held in 1958. Aramburu's military government forced Perón into exile and barred the Peronist Party from further elections. Perón lived in exile in Spain until 1973 under the protection of Generalísimo Francisco Franco.
Anti-Peronist political power
After the end of his presidential term in 1958, Aramburu retired from the military career and devoted himself entirely to politics. He ran for president in 1963 as leader of the Union of the Argentine People, with the slogan "Vote UDELPA and HE won't return", referring to Perón. With the Peronists banned, the Presidential elections resulted in Arturo Umberto Illia becoming president, with Aramburu coming in third. Yet the military retained much real power, censoring both Peronism and its leader. The fragility of Argentine democracy was shown when Illia was overthrown in 1966 by a military coup led by General Juan Carlos Onganía. In 1970, he was mentioned as a possible presidential candidate.
Death
On May 29, 1970 at noon, Aramburu was snatched from his apartment in Buenos Aires by two members of Montoneros posing as young army officers. Montoneros dubbed the kidnapping Operación Pindapoy, after a company that produced citrus in the 1960s. Aramburu's disappearance kept Argentinian society on tenterhooks for a month before it was discovered that Aramburu had been murdered three days after his abduction, following a mock trial and his corpse hidden inside a farmhouse near Timote, Carlos Tejedor, in Buenos Aires Province. He had been shot twice in the chest with two different pistols. Following his arrest, convicted terroristMario Firmenich took credit for the kidnapping and assassination. In the following weeks, statements from the Montoneros flooded the media. Among other things, they claimed their actions where a response to the executions of twenty-seven peronist militants that took part in an unsuccessful coup d'état in 1956. Aramburu's murder and the coldness with which it was carried out shook Argentine society to its core. Montoneros justified by Aramburu's execution as a way avenge a series of executions following the botched attempt to overthrow the state in 1956. However most of Argentine society respected Aramburu and as he had been a voice for the return of democracy at a time when the military was still unwilling to allow elections. In 1974, Aramburu's body was stolen by Montoneros. The corpse was to be held until President Isabel Perón brought back Evita Perón's body. It was also an act of revenge for the previous removal of Evita's body. Once Evita's body arrived in Argentina the Montoneros gave up Aramburu's corpse and abandoned it in a street in Buenos Aires.