Bingo! How did the Nazis gain power. From exploiting the fear of Bolshevism, as justified as such fear certainly was. The anti-semitism was there, but most of the Nazi campaigns focused on eradicating Bolshevism, and since many felt that the Nazis were the only alternative to Bolshevism, that is what drove their support.
And given what Stalin did to the Ukrainians and anybody else who did not give him full support, if the Nazis did not come to power (and result in the US coming in), Europe would have fallen to Stalin within a decade or two. The bloodbath would have been bigger. It would have involved different people getting killed, but it would have been bigger.