I don't imagine my high school literature or history teachers easily challenging him. My class lecture's would have sounded like "and here Hitler said x, it's n

I don't imagine my high school literature or history teachers easily challenging him. My class lecture's would have sounded like "and here Hitler said x, it's not true because of y and he was saying it to blame Jewish people for z problem." And the multiple choice quiz at the end of the week sounds like a complete mess. If it were trivial to counter it as a poorly written book, it never would have gained the influence it has. A well intentioned mediocre teacher could lead to people agreeing with the book, and I'd guess making Mein Kampf a mandatory study would also draw in a lot of teachers that aren't well intentioned.