There was a woman in a bookstore breathlessly telling her friend that there is a conspiracy to change the Constitution, make America into a UN protectorate, and force us all to eat genetically engineered food. There were "Trust Jesus" plaques along the roadside. And graffiti in public restrooms such as those in the picture above. The narrative is clear: a governmental conspiracy; a vast network of lies that obscures the simple truth of religion and/or Constitution. What Richard Hofstader called "The Paranoid Style in American Politics" in his classic 1964 essay is alive and well: http://karws.gso.uri.edu/jfk/conspiracy_theory/the_paranoid_mentality/the_paranoid_style.html
But what is more significant is WHY it is so popular. It has nothing to do with mental illness or with the recent ridiculous suggestion by Chris Mooney that conservatives are genetically different from liberals (does living in Fresno instead of San Francisco affect your genome?).
No, conspiracy theories are popular because they are narratively stronger than wishy-washy liberalism. The woman I overheard in the bookstore had a narrative that seamlessly connected Obama, GM food, and her own depleted bank account. Adrift in a big, complex, chaotic world, she needed a story to cling to. This story is wrong but it is as compelling and dramatic as a Hollywood movie. It has no historical truth on its side but it has narrative truth and in a fight between the two, narrative truth always wins.
Democrats, aghast at the irrationality of the Republican debates, marshal facts and statistics. They'd do better to consult a script-writing textbook that could teach them the basic elements of storytelling. Or perhaps a course in narrative theory should be mandatory for politicians (I wish!)