Hitler was a socialist. Nazi is short for Nationalsozialistische Deutsche Arbeiterpartei (The National Socialist German Workers’ Party) and the red in the flag was adopted to make it easier for communists and socialists to switch to the Nazi Party.
IIRC, Hitler was a social democrat. Think I used Socialist incorrectly. I believe the word I was looking for was Marxist.
Hard to understand that. I don't think that the Nazis did much of an outreach to the communists and socialists, but rather treated them as enemies in Germany, even though the Nazis themselves had "socialist" in the party name. For example, the infamous Reichstag fire in 1933 was blamed on a Dutch communist, and socialists and communists (as well as others who didn't follow the Nazi line) were forced out of the Reichstag (parliament) soon after Hitler was named chancellor.
I know that for a two year period between 1939-41 when the Nazi-Soviet non-aggression pact was intact, communists around the world, including in the US, were silent as Hitler started WWII and Germany invaded and occupied quite a number of European nations. Then the communists worldwide reversed themselves again in June 1941 when the Germans launched their surprise attack on the Soviets.