"I now believe the 9/11 Truthers I encountered were canaries in the coal mines of American society," writes our co-host, Jim Meigs, in the current issue of City Journal. In this episode, we hear about conspiracy theories, those who believe in them, and the corrosive impact of paranoia on American political life.

Richard interviews Jim about his work at Popular Mechanics in the years after the 9/11 attacks. A team of reporters, editors and fact-checkers at the magazine interviewed more than 300 experts and sources in civil engineering, air traffic control, aviation, fire fighting and metallurgy. Their findings were published in the 2006 book, "Debunking 9/11 Myths. Why Conspiracy Theories Can't Stand Up to the Facts."

Jim also asks Richard about his reporting from the streets of Manhattan in the hours and days after the attacks that brought down the North and South Towers of The World Trade Center twenty years ago.