I don't think it's fair to say 40% of Americans.
He only had ~74M votes in the last election, and he still lost. That equates generously to around 1/4 of all Americans (329M), back then. If the support numbers haven't shifted, that's still significantly under 25% of Americans that are too stupid to be left alone with a box of crayons.
It's considered a "fantasy document" alongside the "World Government Passport"