But the vast majority of those problem police are governed by liberal or progressive governments. Those police agencies should be models for the rest of the country and the world absent any involvement by the federal government.
To make it worse, a large part of the blame lies on police unions, e.g. in Minneapolis, whose leaders are hard authoritarian/right-wing and use all powers they have including staging expensive and often successful legal battles to keep "bad apple" cops in the service instead of holding them accountable.