When I was a child, I thought the same question as you have, How on earth? I heard many accounts firsthand of Hitler's natural affinity for scorching, grandiose, speeches and geometrically ostentatious march rallies, still, I wondered why people would accept such a Psychopath as a leader of government. Just as you have stated, now I know.
I'll take the words of a man who lived through such barbaric Communist government, and who helped propagate it worldwide. His supporters will not wake up until it is too late...
"A person who is demoralized (by Marxist/Leninist indoctrination) is unable to assess true information, the facts mean nothing to him. Even if I shower him with authentic information, with documents, with pictures. Even if I take him by force to the Soviet Union and show him concentration camps, he will refuse to believe it until he is going to receive a kick in his fat bottom. When the military boot crashes, THEN he will understand, but not before that. That is the tragedy of demoralization of a nation."
Yuri Bezmenov, KGB Defector, former agent in the propaganda wing of the KGB.