In the 1950s, Disney started using Mickey Mouse in ads with slick, modern design. But that came crashing to a halt for political reasons during the Red Scare. Here’s artist Victor Haboush on what happened (quoted in Cartoon Modern):

There was a little kid that used to write Walt telling him to stay away from modern art because it’s Communistic. So when the commercial came on, he got a letter from this kid, a little malcontent sitting somewhere, and he wrote, “I’m disappointed Walt. I never thought you’d succumb. What happened to you?” and Walt went crazy. He stormed down there and outlawed us against using any of the Disney characters in the commercials. I remember at the time everybody was incensed that we couldn’t use them, and it basically spelled the end of the unit.