Zeinab Badawi talks to Linda Thomas-Greenfield, the US assistant secretary of state for African affairs. Barack Obama is due to visit Kenya, his father's homeland, next month. When Obama came to power as the first African-American president of the USA, hopes were high in Africa that the continent would bask in his reflected glory and enjoy a new focus in US foreign policy. Zeinab Badawi asks: does Obama have a vision for Africa?