People claimed that the Genocide of Jews by the Nazis was just Jewish propaganda. (The same accusation had been made about the Armenian Genocide that had inspired Hitler yemach shmo.)
And that there wasn’t any real hard evidence.
And that the media was making it up.
And that Hitler was justified because Germany had been badly treated in the peace conference after WW1.
And that we should support Hitler because he went to war with Stalin.
And that Churchill and Roosevelt were despicable.
Goebbels was very successful at his propaganda and we now see that Putin is today.