My (now-deceased) stepfather was Jewish and a historian. He focused on WWII and the US Civil War. When he and my mom went to sell their house about 12 years ago, the listing agent walked through and said, "Oh, you should probably clear out the bookcase a bit."

My stepfather had more than an entire shelf of books on Hitler in the living room as he had been working on an article about him.

Needless to say, my stepdad took the hint.