The morning sessions were coming to an end when we led David Remnick through the Hay festival site in search of a quiet place to conduct an interview; the walkways clogged with pedestrians, the air full of noisy chatter. We had timed it wrong and could barely move. "It's like an American high school between classes," Remnick said.

The Pulitzer prizewinning author was making a flying visit to the festival to discuss The Bridge, a weighty, compelling account of the making of Barack Obama and – by implication – modern-day America itself. The title refers to the Edmund Pettus bridge in Selma, Alabama, the scene of a violent stand-off between police and Civil Rights demonstrators in March 1965. It was a conflict that led directly to the passing of the Voting Rights Act just two months later, an act whose ripples are still being felt almost half a century later. According to one of the demonstrators on that march, "Obama is what comes at the end of that bridge".

On a sheltered patch of grass, Remnick discussed the significance of Barack Obama: a cool cultural linguist, a mediator of racial politics and a man (in the words of Colin Powell) who ran for office as "an American who is black as opposed to a black American". We also discussed the author's day job as the editor of the New Yorker magazine, which this week runs an article ("20 Under 40") spotlighting the best young fiction writers in North America.

Once upon a time, perhaps, Barack Obama might have been among them. In his 20s, the future president wrote a number of short stories, and various friends and colleagues assumed he would go on to be a novelist. But fate took him in a different direction. His facts were to prove richer, wilder and more inspiring than his fictions.