It seems that Joel Olson not only specialized in studying extremism and fanaticism, but also White Guilt. The description of one of his books: http://www.upress.umn.edu/Books/O/olson_abolition.html

"Joel Olson contends that, given the history of slavery and segregation in the United States, American citizenship is a form of racial privilege in which whites are equal to each other but superior to everyone else. In Olson’s analysis we see how the tension in this equation produces a passive form of democracy that discourages extensive participation in politics because it treats citizenship as an identity to possess rather than as a source of empowerment."