Books shouldn't be banned, period.
Book-banning is one of the more obvious marks of totalitarianism.
Some books should be banned...like if some wrote a book about banning books, that book should be banned
Then you have to establish an authority to decide what should be banned, and after that it won't be long before that authority starts being abused for political purposes, exactly as we are already seeing too much of today.
The best way to defeat a bad idea is with a better idea, with both of them given free and open access to public discourse and debate.