As they say history comes in cycles. Everyone knew that it was about racism because fascism always needs an enemy and if no convenient enemy exists one has to be manufactured, in 1930s Germany that was the Jews. They were always a good target because a lot of other religions disallow money lending which means that all the money lending was done by the Jews, because no one else was allowed to do it. Obviously people don't like owing other people debts (especially if they can't afford to pay them back) so they tend to have negative opinions towards them, and by extension their religion.

But nobody in Germany with half a brain really thought that the Jews were responsible for the country's economic woes, they all knew very well that it was reformation payments for the first world war. But it was so much easier to blame someone else so they went along with it. Of course no one knew how far it would go but they definitely knew that Hitler had nothing in the way of solutions he was just good at rhetoric.