>>most of those Soviet favoring films were essentially war porpaganda that was sanctioned by the goverment.<<
Yup. Once Uncle Joe turned on the Nazis, the enemy of our enemy became our friend. And since the liberal elites in both Hollywood and the government had always been sympathetic to the Soviets anyway, they regared this as a natural evolution toward a better world.
Remember that during the Depression, many Americans came to believe the capitalist system had failed and that socialism/communism was the solution. After WWII, when the Soviets began to take over eastern Europe, and the truth about purges, mass starvation, etc., began to come out, most Americans turned away from the Soviets. Liberals, however, never did. They promote socialism to this day.
They turned away from Stalin. Who modern communists claim perverted their movement. But in the 1930s communism in America was much more common and mainstream then it is today. It seems like every other American film of the 30s was based on class differences in some way.