One of the enduring myths of the Nazi era is that average Germans didn’t know what was happening to persecuted groups including the Jews. Everyone knew about the round ups and the deportations – they were impossible to miss in daily life.
However, for many Germans, the concentration camps were not seen as part of a program of political and racial terror, but a sensible policy, which sought to deal with the problems of uncontrolled immigration of Jews from the East and with the socially and politically deviant.
Although Nazi propaganda emphasized a world Jewish conspiracy that posed an existential threat to the racial purity of the „Aryan“ people, there was also an extensive effort to link Jewishness to problems of everyday criminality.
An excerpt from an article I’m currently writing on anti-narcotics policy in the interwar era:
For those who were not convinced of the conspiratorial antisemitic worldview, prejudicial views of Jews as inherently criminal provided an alternative justification for mass detention. From KL: A History of the Nazi Concentration Camps by Nikolaus Wachsmann
On the one hand, the Nazis wanted people to fear the camps, but they also wanted to reassure German supporters who would be squeamish about outright sadism as well as foreigners, that conditions were humane. For Germans after the war, this provided the alibi that they knew nothing of what was going on at the camps. They merely supported a state policy to take deviants away from society to be housed in humane facilities where they could do no harm.
There was excessive evidence of the horrors of what was happening in the camps and the violence and death inherent to the Nazi project, but the Third Reich provided its citizens a veneer of respectability that they could cling to as a shield to avoid confronting this reality.