After 55 years of disciplined unity, South Africa's ruling party is engaged in a bitter dispute over leadership, which could determine who will be the country's next president. President Thabo Mbeki cannot run for a third term in 2009. Today, he's being challenged as leader of the African National Congress, the party that's ruled the country since apartheid ended 13 years ago. Jacob Zuma, fired as Mbeki's deputy, leads the opposition and is a popular figure. We get an update from Craig Timberg, Johannesburg Bureau Chief for the Washington Post, and Stephen Smith, Professor of African Studies at Duke University and former Africa Bureau Chief for Le Monde.