He showed hints of it when the tea party was taking off, but it was fairly level-headed stuff. The descent into madness was gradual, and I feel blessed to read his earlier posts where a germ of the madness started off.
I was never into Dilbert but my parents got me that big collection of them where Scott Adams leaves little comments on them in a sort of marginalia way. It was before a large car trip and I think they thought it would be just funny cartoons like Calvin and Hobbes (which I'd read earlier) to keep me entertained. And so for some reason I can remember certain Dilbert comics in crystal clarity including Scott Adams opinions on the reaction at the time.
Weirdly a similar thing happened to Mattie Lubchansky author of the Antifa Cookbook and Boys Weekend.
I had several of the cartoon books, but the only one I remember specifically is the one where Dogbert asks a recruit for the holy war (Linux vs Windows, I think?), "Can you chant?"