SANDTON, South Africa — Kenny Kunene, a former gangster turned businessman, gave what he called “the mother of all parties” for his 40th birthday. With his small paunch protruding from a white tuxedo and his eyes hidden behind Roberto Cavalli sunglasses, he ate sushi from the belly of a woman who was wearing nothing but black lingerie and high heels while hundreds of guests looked on.

Mr. Kunene, who says he supports the A.N.C.’s Youth League with his time and money, promptly retorted that his was “honest money spent on honest fun.” He describes his success as proof of the nation’s democracy, and he told Mr. Vavi, who is also black: “You remind me of what it felt like to live under apartheid. You are telling me, a black man, what I can and cannot do with my life.”

The Kunene story has crystallized a recurring question about life in post-apartheid South Africa: Is the accumulation and exhibition of such wealth a sign that blacks have finally arrived after an era when whites hogged the high life, or is it evidence of a moral decay undermining Nelson Mandela’s once great liberation movement?...

He was raised by his unemployed mother (an evangelical faith healer), his grandfather (a retired English teacher), and his grandmother (a midwife and the family’s only earner) in a black township outside of Odendaalsrus in what is now the Free State. The family could never afford to give him a birthday party, he said, and he always craved luxuries.

When he was a teenager during apartheid, he said he and his friends picked out the houses and cars in wealthy white areas they fantasized would one day be theirs. He dreamed of Porsches. “The objective was to overthrow the government and take everything that the white man had,” he said....