Before the advent of Photoshop, being a photmontage artist was a fairly complicated endeavor. For John Heartfield, a German citizen who chose to speak out against the National Socialist Party through his work, it was even more difficult.
Born in 1891 as Helmut Herzfeld he saw the horrors of the First World War first hand. Although propaganda was rife and rabid on both sides he made the extraordinary move of anglicizing his name in 1916, in the middle of the war, to protest against such nationalism.
That, of course, was just the beginning. See more of Heartfield's photmontage series and read the history of his life and work on Kuriositas. Link
Image credit: Smabs Sputzer
Hitler was a very charismatic individual who could manipulate the passions and desires of those already stuck on the wheel, while he himself remained firmly nailed to it. This may be comparable to "Leader Worship" but this is to use "worship" in the sense of adoration and perceived value, which is its original meaning.
Our societies worship money, celebrity and sex, and in the name of our Gods we kill people. We just don't see it because we have highly charismatic leaders and because we are all stuck upon the wheel. We think we are doing the right thing.
Alternatively we could think that an entire nation of civilized human beings up and desired to kill Jews arbitrarily, with no reason, and by exercising their "free-will". Which is patently not true when we learn of dissenters like Heartfield. Indeed, we could believe the entire world and everyone in it except for us and ours is completely mad. We could all do that and we'd be exactly where we are.