There is no standard definition of the all-important term “wing nut,” so let’s provide one. A wing nut is someone who has a dogmatic commitment to an extreme political view (“wing”) that is false and at least a bit crazy (“nut”).
A wing nut might believe that George W. Bush is a fascist, that Barack Obama is a socialist, that big banks run the Department of the Treasury or that the U.S. intervened in Libya because of oil.
When wing nuts encounter people with whom they disagree, they immediately impugn their opponents’ motivations. Whatever their religion, they are devout Manicheans, dividing their fellow citizens into the forces of light and the forces of darkness.
Wing nuts have a lot of fellow travelers — people who don’t fit the definition, yet who are similarly dogmatic and whose views, though not really crazy, aren’t exactly evidence-based. You can be a wing nut on a particular issue without being a wing nut in general. Most human beings can hear the voice, at least on occasion, of their inner wing nut.