Matthew Dallek’s “Birchers” traces how conspiracy theories went from being a fringe pastime to the right’s defining feature.

Q's followers were promised a war. Now, as federal agents snatch people off the streets, they believe it's arrived.

Crank ideas have always flourished in times of great instability and inequality.

How William Cooper envisioned a web entangling global capitalism, the government, and UFOs, and incubated the politics of conspiracy

Trump isn’t the first conspiracy theorist in chief—just the most shameless.