American author and playwright Gore Vidal, who unsuccessfully ran for political office twice, has died at the age of 86.
The announcement was made Tuesday night on his official website, but did not mention a cause of death. Vidal's nephew, Burr Steers, said he died of complications from pneumonia, according to The Associated Press.
Vidal had been living alone at his home in Los Angeles and had been sick for "quite a while," he said.
Vidal's works included hundreds of essays and bestsellers such as "Lincoln," "Myra Breckenridge" and the Tony-nominated play "The Best Man," which was recently revived on Broadway.
"The City and the Pillar" was one of the first novels to include openly gay characters when it was published 1948.
Vidal also appeared in a number of films, including the political satire "Bob Roberts," where he played a U.S. senator. More recently, Vidal voiced himself on both "The Simpsons" and "Family Guy."
He was the Democratic candidate for Congress in an upstate New York district in 1960. In 1982, Vidal came in second in the California Democratic senatorial primary. He lost to incumbent Gov. Jerry Brown.
Vidal's connections to the political world didn't end there. He shared a stepfather, Hugh Auchincloss, with Jacqueline Kennedy. His grandfather Thomas Gore was a Democratic senator from Oklahoma. His father, Gene Vidal, served briefly in President Franklin Roosevelt's administration and was an early expert on aviation.
Vidal never shied away from giving his opinion on subjects, especially politics. Vidal squared off with conservative William F. Buckley in 1968 prior to the 1968 election on ABC News. Vidal accused Buckley of being a "crypto-Nazi." Buckley threatened to slap Vidal in the face.
In an interview with the New York Times in 2008, he was asked to comment about Buckley's death. "I thought hell is bound to be a livelier place, as he joins forever those whom he served in life, applauding their prejudices and fanning their hatred," Vidal said.
In that same interview before the 2008 election, Vidal called Sen. John McCain a "disaster."
"Who started this rumor that he was a war hero? Where does that come from, aside from himself? About his suffering in the prison war camp?" Vidal said.
Vidal accused the George W. Bush administration of having advance knowledge of the Sept. 11, 2001, attacks. Vidal formed his most unusual bond with Oklahoma City bomber Timothy McVeigh.
"He's very intelligent," Vidal said of McVeigh in a 2001 interview. "He's not insane."
Vidal was born Oct. 3, 1925, at the United States Military Academy in West Point, N.Y., his father's alma mater. Vidal was primarily a self-educated man. He enlisted in the United States Army at 17 and became a warrant officer at 19. While in the Army, he wrote his first novel, "Williwaw," which was published in 1946.
In addition to his novels, Vidal wrote a number of scripts for television such as "The Death of Billy the Kid" and the screenplay for the Hollywood film "Suddenly, Last Summer."
Vidal is survived by his half-sister Nina Straight and half-brother Tommy Auchincloss.
The Associated Press contributed to this report.