University of Johannesburg Professor Adam Habib has been able to return to the United States after being excluded since 2006. The American Civil Liberties Union sued on behalf of the American Sociological Association, the American Association of University Professors, the American-Arab Anti-Discrimination Committee, and the Boston Coalition for Palestinian Rights to get Habib back into the country. Then in January Secretary of State Hillary Clinton lifted the exclusion against Habib's visa. Habib this weekend spoke at the American Sociological Annual Meeting in Atlanta. What changed? Why did the United States permit him to enter? Don Lemon sits down with the once-banned professor.