I was answering this question and thought that we have asked about the inclusion of those wacky nazis and inspiration derived from their intolerant ideology in science fiction and fantasy many times. A rapid search for the term throws 264 results.
I was going to create the tag but on second thought maybe such a tag is kind of controversial or not needed. What do you think? Would it be offensive to create such a tag? Can it be useful?
Edit: do you think a tag named [nazi-villains] is a good compromise in order to avoid possible problems but at the same time adress the issue?