Isabel Allende is the niece of Salvador Allende, who was President of Chile from 1970 to 1973 when he was deposed by a military coup. Allende was the head of the so-called coalition of "Popular Unity", a left-wing alliance between Socialists, Communists and other Progressive forces. Allende was the first Socialist to be democratically elected as the head of government in a Latin American country. The result was extremely close and his policies of nationalization and collectivization stirred virulent opposition from the Chilean right and from the Nixon Administration. These two forces orchestrated the military coup which ushered in the violent dictatorship of General Augusto Pinochet, leading Allende to commit suicide rather than surrender. The exact date was September 11th, 1973, twenty-eight years before the terrorist attacks against the Twin Towers.
Isabel Allende has often stressed that the coup was a defining moment in her life which caused her to flee to Venezuela with her family. During this exile, Allende wrote The House of Spirits where she never mentions Chile by name, but which is clearly about the history of Allende's home country before and after the Popular Unity. In the novel, the Socialist Candidate is a clear reference to Allende and his actions to address social injustices are frustrated by the right-wing conspiracy to cause food shortages.
If you're interested, there is a film adaptation of The House of Spirits by Bille August starring Antonio Baderas, Meryl Streep, Glenn Close, Jeremy Irons, Vanessa Redgrave and Winona Ryder. An interesting episode in the collective movie September 11 details the role of the CIA in overthrowing a democratically elected government. The episode, directed by Ken Loach, denounces the American involvement in a terrorist act and argues that September 11th should not be remembered only as the date of the attacks against the Twin Towers, but also against the Chilean Presidential Palace, La Moneda. Finally, a good documentary on Allende and his government is Salvador Allende (2004) directed by Patricio Guzman.