Why do you think that Hitler is seen today as one of the most evil political leaders who ever lived?

Enormity of world war II as the most destructive war ever,
and that of Holocaust as the most horrible genocide ever are unquestioned, and Hitler
may be held primarily responsible for both. However, It is only the Holocaust that
really makes him the Most evil political leader.

Hitler had
many justifications for trying to improve the power and position of Germany, and his
aims and actions were no more evil than those of other countries who colonized and
exploited other countries, making claims to be "empire over which sun never
set".

But merciless killing of Jews by Hitler has no other
parallel in history, and on that count alone, I would rate Hitler as the political
leaders who caused maximum death and destruction of innocent people in a very cruel
way.