Obama dissed him because of Brit colonialism in Kenya, IIRC.
In 2012, D’Souza released his film 2016: Obama’s America, an anti-Obama polemic based on D’Souza’s 2010 book The Roots of Obama’s Rage. The book and movie present the view that Barack Obama’s attitude toward America derives from his father’s anti-colonialism and from a psychological desire to fulfill his father’s dream of diminishing the power of Western imperial states. The film was the highest-grossing conservative documentary film produced in the United States.[8]
https://en.wikipedia.org/wiki/Dinesh_D%27Souza