Although identified only as Frank in Mr Obama’s memoir Dreams from My Father, it has now been established that he was Frank Marshall Davis, a radical activist and journalist who had been suspected of being a member of the Communist Party in the 1950s.
Mr Davis moved to Honolulu from Chicago in 1948 with his second wife Helen Canfield, a white socialite, at the suggestion of his friend the actor Paul Robeson, who advised them that there would be more tolerance of a mixed race couple in Hawaii than on the American mainland.
A bohemian libertine who drank heavily and loved jazz, he became friends with Stanley Dunham, Mr Obama’s maternal grandfather in the 1960s. Mr Davis died in 1987 at the age of 81, five years before Mr Dunham.
“He knew Stan real well,” said Dawna Weatherly-Williams, a close friend of Mr Davis “They’d play Scrabble and drink and crack jokes and crack jokes and argue. Frank always won and he was always very braggadocio about it too. It was all jocular. They didn’t get polluted drunk. And Frank never really did drugs, though he and Stan would smoke pot together.”
While his mother was in Indonesia during part of his teenage years, Mr Obama lived with his white grandparents. Mrs Weatherly-Williams said that the poet was first introduced to the future Democratic presidential candidate in 1970 at the age of 10.
Read More: By Toby Harnden, UK telegraph