How is this movie racist?
Is it because of the roustabout scene? Well, yes, they were all black men, but this was common in the 1940s, a majority of African Americans were migrant workers who handled menial jobs, which are usually performed by Hispanics today.
This scene isn't racist. If you'll notice, they're working hard. They're not just sitting around playing craps and eating watermelon. These guys are hard workers. Erecting that big circus tent over the course of one night. Sure, they're singing about never learning to read or write and things like that, but again, this was 1941. Schools were not integrated yet, so a majorty of African American children were not permitted in schools (not the so-called 'good' ones for whites).
What about the crow scene? Is it because the lead guy is named Jim Crow? Sure that's another slang term, but in this case, the character is a crow named Jim. As for the other crows, all voiced by African American men. Jim is voiced by Cliff Edwards, who was white, but he doesn't do an over-the-top mammy voice.
Therefore, Dumbo is not racist, it just reflects the times.
Same with Song of the South. How is that racist? Uncle Remus is a naturally happy man, not just a so-called "happy slave" as this movie was set after the Civil War), and as for the cartoon characters: Brer Rabbit, Brer Fox and Brer Bear were all voiced by African American men. Not white guys doing exaggerated impersonations.
Therefore, Song of the South is not racist either. Just reflecting the times.