You know, as long as there has been history, there have been assholes to mess it up. So let's take some time to mark the biggest assholes in the history of mankind. I've selected my picks, feel free to offer your own if you find my list lacking. 
an explanation of some:
The Inquisition was certainly not one person (but a very funny MP sketch), it inspired ever more horrendous religious persecution under the guise of official sanction. Thus it trumps the Salem Witch Trials, all the religious wars, George W' Bush's administration, etc. :p
Andrew Jackson was rabidly anti-Indian, and forced the migration of thousands of Cherokees along the Trail of Tears. Somewhere in hell, he's sharing a pineapple up the ass with Stalin and Hitler.
I don't recall the guy who founded the KKK, but he was a Confederate veteran in Tennessee around 1866 who really didn't get it that the war was over. He also didn't get it that murdering former slaves is just as wrong as having them as slaves in the first place.
Huey Long was the governor of Louisiana who could very well have been a tyrant in the making had he not been gunned down in 1935. There may be efforts to revise his legacy and hold him up as a good man. But the facts speak for themself. Certainly not a fascist dictator on the scale of Hitler or even Mussolini, but he could've been...
The EG Border Patrol, specifically the one that guarded the Wall, killed countless individuals seeking freedom from Commie oppression. However many threads there are now about Communisium :p
The dicks at NASA who pushed the Challenger mission even though there was evidence of potential danger are assholes, no question about it. But they obviously aren't as dense as whoever pushed the Columbia mission as well. Twenty years pass and NASA still doesn't get it: if you send people up in faulty aircraft, they die.
I fucking hate hackers. Fucking hate all of them. They need to be neutered and spayed, and given the old "Johnny Got His Gun" treatment (no arms, no legs). Also, whoever invented spam, email viruses, and all pop-ups just needs to die.
I almost put Bush, but he never ordered thirteen guys to fly some planes into buildings full of people. Only one guy did that, and he's an asshole more than Bush.
Anyway, feel free to reply with your own "asshole" if my list does not suffice.
