Gore Vidal is indeed a relative of Al Gore. Vidal throughout his life claimed he was an Oklahoman sometimes, a Southern gentlemen sometimes and acted like a Boston Brahmin all the time. In fact, when Al Gore was running for Veep, many people sought out Vidal’s opinion on his cousin (I forget the exact relation). His opinion was not good as I recall.
They are not related. See this foot note to the genalogy of Al Gore
Ancestry of Al Gore
compiled from various sources, some of whom, notably Michael Pollock (mpollock@mindspring.com), Kees van den Berg (kkees@worldonline.nl), Dawna Lund (DawnaJL@aol.com), and Raymond L. Maris (raymond@maris.net) can be publicly acknowledged.
FURTHER NOTES
Several persons have claimed that the author Gore Vidal is related to Al Gore. While it’s true that all of us are related, it doesn’t appear that Al Gore and Gore Vidal share any traceable Gore ancestors.
Eugene Luther Vidal, Jr., alias “Gore Vidal”, was born in Washington, D. C., on 3 October 1925, the son of Eugene Luther Vidal and Nina Gore, daughter of Sen. Thomas Pryor Gore, U.S. Senator from Oklahoma 1907-1921 and 1931-1937 by his wife Nina Kay. The National Cyclopedia of American Biography, in Vol. XXXVI [1950], on p. 22, says that Sen. Thomas Gore was a son of Thomas Madison Gore and Caroline Elizabeth Wingo, a grandson of Ezekiel Fletcher Gore and Mary Green, a great-grandson of Thomas T. Gore and Nancy Sanders, and a great-great-grandson of James Gore, who came from Ireland about 1775 and settled in Frederick County, Maryland.
As shown above, Vice President Al Gore’s immigrant Gore ancestor was John Goare of Middlesex County, Virginia, who arrived before 1677. If there was any connection between James Gore and John Goare, it would have to have been before they emigrated (separately) to North America, but their origins are (currently) unknown.
http://www.wargs.com/political/gore.html