Some people just have a need to fervently hate something and/or find something to be fanatically devoted to, just to give their lives a sense of purpose.
Roland Freisler was a foaming-at-the-mouth German Communist until he did an about face and became an equally foaming-at-the-mouth Nazi. He's the judge who presided over the kangaroo court for the "Valkyrie" conspirators who tried to assassinate Hitler. He forced an elderly General among the accused to appear in court without his dentures and belt, then screamed "stop playing with your pants, you dirty old man!". There was also a video clip I saw on an old WWII documentary where one of the accused is trying to explain why he turned on Hitler, and he mentions "the many murders" (referring to the Holocaust), and Freisler just goes ballistic and starts screeching at the top of his lungs that the guy is lying, treasonous scum, etc., like the very suggestion that the Nazi regime would commit murder is the most outrageous thing he's ever heard of (this despite that Freisler was at the Wannsee Conference where the Holocaust was hammered out and planned in sickeningly laborious detail). He was nicknamed Raving Roland. Freisler was nuts.