Bad ideas traveled fast without even the benefit of the Internet. Heavy drugs helped (though Nixon didn’t seem to need anything more than alcohol). Conspiracy theories spawned theories of who benefited from conspiracy theories. There was gold at the end of Gravity’s Rainbow. Even Oliver Stone was not necessary. For example, Wheen notes, “It was A Clockwork Orange which convinced [Arthur] Bremer that he must shoot George Wallace [because he couldn’t get close to his first choice, Nixon], and Bremer’s assassination diaries then inspired Paul Schrader to create the character of Travis Bickle. So: without Bremer there would be no Taxi Driver, and without Taxi Driver John Hinckley Jr. wouldn’t have become so obsessed by Jodie Foster that, to prove himself a worthy rival to Bickle, he shot Ronald Reagan.” He’s not making this stuff up.
The whole review is worth a read. Also, this gives me an idea for Gitlin's next project.