@blueveinedthrobber,
What leaps to my mind was Dubyah...but he wasn't evil. He clearly was unaware of the big picture and that made him dangerous. I felt that his lack of results and his non-action caused evil things to happen, but I don't feel he personally was evil. I cursed him during hurricane Katirna and during the 9/11 tragedies.
Now, within his administration, when it comes to evaluating VP Cheney, I would say he is where the evil is and was.
Being that I'm 62, perhaps I have a longer view of US political history. I would categorize the late Senator Joseph McCarthy of Wisconsin, as evil.
These are my top 2!