A lesson from Kevin Kruse's White Flight.
Racist policies were preferred by the local power structure. In order to defeat these policies, the Feds had to overrule the local laws and customs in the 60s.
Part of the White response was to flee to suburbs and build a de facto segregationist society. This is where a great deal of the "local control" and "localism" movement comes from.
Thought experiment:
What happens in a democratic society when the majority is viruently bigoted?