evidence: Former South African President Nelson Mandela is universally admired but there was a time when he was caught up in controversy. Steve Inskeep talks to Bill Keller, a columnist for The New York Times, about Mandela's controversial past. Nelson Mandela is universally admired today, but was a controversial figure for much of his life. To reconstruct what that controversy was about, we turn to Bill Keller. He's a New York Times columnist and former executive editor who once covered South Africa, and wrote a youth biography of Mandela.