Not a Dem, but this is like asking between Voldemort and Professor Umbridge; Sauron or Denethor; Palpatine or Jar Jar Binks.
I have to completely disagree with the first comparison. People often say Umbridge was "just" a mean person and bad teacher compared to the genocidal Voldemort, but actually if you look at her bigoted statements against "inferior" beings and her actions in the final book, she was clearly a gleefully willing participant in a genocidal regime. She actually reminds me a LOT of
Roland Freisler, the leader of Hitler's Kangaroo Court who condemned the likes of Sophie Scholl and the July 20 plotters to death in sham trials which mostly consisted of him berating and screaming at the defendants about how they dared to defy Der Fuhrer.
The similarities are so uncanny I find it hard to believe they weren't intentional by Rowling, who clearly intended the series in the end to be an allegory to Nazi Germany. And Freisler (who was so evil that when he died in an ironic Allied bombing which literally brought his own court crashing down around him, no one objected when someone at the hospital said "It is God's verdict" upon seeing the corpse) was hardly "better" than Hitler. Indeed, as someone who works in the legal system, seeing a man like that pervert justice and the law in such a sickening and cruel way actually strikes me on a visceral level as more messed up than "just" an ambitious cutthroat politician like Hitler ever could.
This man took what's supposed to be the great equalizer of people -- the justice system -- and weaponized it as an instrument of torture and genocide. Umbridge does much the same in the final Harry Potter book. I hope there was a Nuremberg Trials equivalent in the wizarding world and she was sentenced to life in Azkaban.
Oh and she also literally tortured a child and sent literal soul-sucking demons to murder him. So there's that, too.
Poll
