So if a book is banned by a widespread movement of extremists taking control of local governing bodies and the federal government is not involved, that's okay then?
that was the only point I was making. Mein Kraft, Selected Works of Lmao The Dong, and The Anarchist Cookbook may be removed from sale/access in some specific locations, but it is very much legal to buy, own, and sell them.
the US federal government historically banned books under the Comstock Act of 1873 which is still on the books and is still active federal law. it only currently isn't being enforced following some cultural changes in the 1960s. another change in the cultural winds could bring it back unfortunately
don't you have lots of those dormant old timey laws that would be promptly invalidated as unconstitutional if an attempt to enforce them was made these days, like sodomy laws were?
the Comstock act was unconstitutional at the time that it was actually enforced. i don't want to get into politics but there are many dynamic factors at work here