Conspiracy theories used to weave together random bits of evidence with speculation on secret, nefarious actors working behind the scenes -- think the 9-11-was-an-inside-job theory.

Authors Russell Muirhead and Nancy Rosenblum claim that conspiracy theories have changed: they no longer even require evidence, however distorted.

It's enough to claim, as their book's title suggests, "a lot of people are saying..." And the authors are very worried about this trend's threat to democratic norms. They lay out the case in the book, and visit to explain their findings.

