Analysis of the underlying social psychology.
The hate and prejudice that began the Holocaust went hand in hand with a political agenda that was fueled by the frustration aggression theory.(1) Hitler blamed the Jews for the loss of World War I and thus, instead of targeting political aspects of the Jewish community, he displaced his aggression towards ALL Jews, even the helpless.
This, combined with religious anti-Semitism prejudice that had been present in Germany for 1500 years and the theory of "eugenics", was the political and instrumental center of Hitler's political campaign.(5) He used a system of 'elimination of freedom', which he felt was necessary in the conditioning the German people to follow him. This meant that he would slowly change the rules, allowing him to gain more and more control over his people. New laws preventing rebellious attempts to overthrow his government and the elimination of non-supporters that would possibly dissent, (disagree with his plan)(1), gave Hitler complete control over what happened within the country's boundaries.(5) .
He further conditioned the Germans to accept the program for the 'final solution' of the Jews with the constant onslaught of misleading propaganda. Propaganda is the dissemination of ideas and information for the purpose of inducing or intensifying specific attitudes and actions.(4) This misleading information conditioned the German people to stereotype all Jews as evil and thus most of them became prejudice. This was an effect of what is called the availability effect.(1) That is, they made stereotypical judgements based on the information available to them. Many of the Germans had been raised under the influence of this propaganda and it was all that they knew about the Jews, thus, the only available information with which to make judgements by.
Under the umbrella of ethical relativism,(2) these judgements were ethical in relevance to the German culture at this time, and thus, widely accepted by the German people.