Reagan
Some will object to placing Reagan with the likes of Mao and David Koresh. I
happily, nay thankfully, concede that he was not one of the great monsters of
the recent past. The facts remain, though, that he espoused a fantastically
stupid sort of economic miracle cure (which failed; see Krugman, Peddling
Prosperity); revealed not merely an astounding ignorance but a
wealth of positive mis-information about (in no particular order) pollution,
biology, welfare, drugs, the powers available to the police under the American
Constitution, etc. He had no idea whatsoever of history, played on a nostalgia
for a fictional past, was enamoured of absurd technical projects like Star Wars
and publically stated his belief in an immanent, nuclear Armaggedon. (Whether
he believe in that last, or said he did to win support from even more ignorant
voters, is debated.)
No, Reagan was not a devouring monster: just an ignorant, superstitious,
supremely powerful man who may have happened to think that the world ought to
be blown up soon.