Erik Loomis provides us today with an example of the wingnut flower in full blossom, dated 1948:
While carping about race and creed inequality, as a theme song to bring the unthinking masses to his support, he and his wife actually did more to promote creed and race strife than was ever done before in the history of our country or will ever be in the future.and
The Roosevelt administration is directly responsible for our government being hopelessly involved in a debt so great that if it is ever repaid, which is doubt, virtual enslavement to taxes sufficient to kill all initiative will be necessary for the next two hundred years.
I think there is common perception that wingnuttery dates from, and is a reaction to, attempts to extend first-class citizenship to brown people (alluded to e.g. here) but that only goes far enough to explain how the crazy could be made palatable for retail. The real origin is older, and is a reaction to earlier attempts constrain the power of the owner class v. their employees, to the outrage of the former.