Kept seeing this quote and finally found out where it came from. It's a Guardian article.
"Compulsive liars shouldn’t frighten you. They can harm no one, if no one listens to them. Compulsive believers, on the other hand: they should terrify you. Believers are the liars’ enablers. Their votes give the demagogue his power. Their trust turns the charlatan into the president. Their credulity ensures that the propaganda of half-calculating and half-mad fanatics has the power to change the world."