Among high-profile media pundits, Glenn Beck has used some of the most divisive language when speaking about President Obama. Just last week he called Obama a "racist" who "hates white people."
Beck has spent months — literally screaming and crying — insisting that the president is a socialist/fascist/communist/racist who's trying to destroy the country through totalitarian means. Major media outlets have plenty of irresponsible voices, but Beck has been unique in his insane rantings. It wasn't hard to imagine some of his viewers/listeners getting so worked up, they might at least consider doing something dangerous.