Battling cancer, Venezuelan President Hugo Chavez has for the first time named a successor — his vice president. The charismatic, socialist leader with aspirations of regional leadership is in Cuba undergoing a fourth round of surgery. Vice President Nicholas Maduro is a former bus driver who rose through the ranks of his union to national prominence. In an emotional speech, Chavez appealed to his countrymen to elect Maduro to the highest office when Chavez can no longer govern. Audie Cornish talks to Juan Forero.