""The assassination of President Kennedy was a major watershed in American conspiracy thinking – away from the status conscious, angry and white “pseudo-conservatives” who populate Richard Hofstadter’s brilliant articles from the exact time I’m discussing here, and towards a more ideologically diverse group of thinkers. Conspiracy and political paranoia became much more ecumenical after Dallas, spinning off into a raft of new theories, helped along by the FBI’s misdeeds and the Church Commission’s revelations, that culturally mainstreamed the entire enterprise. People who used to hand-crank mimeograph machines to print angry diatribes about fluoride in municipal water supplies morphed into big-money book authors, feature film directors and television documentarians. Just ask Oliver Stone, Jesse Ventura, Bill O’Reilly or members of the Wu Tang Clan who killed JFK, and you’ll see what I mean.""
tl;dr American conspiracy thinking used to be restricted to the right-wing.