“I have found myself watching a lot of movies from the 1930’s and 1940’s. Back when the studios ran the process and one of the primary motives was to make a profit.”
The old movie studios back then told their writers, whether they were left of right, “You want to send a message? Call western union.”
One other factor back then was the large number of Europeans who came to America to escape the Nazis and Communists. They were uniformly grateful that there was an America to come to, and their work in the movies showed that appreciation.