I can't recall a single historical example when "burn it all down and rebuild what's left" actually worked. Europe became the absolute centre of the world for exactly the opposite reason - for retaining and utilising every single scrap we could get our hands on, whether knowledge, resources, or any other advantage. That's one. Even a temporary debilitating weakness of the United States would be mercilessly exploited by the other major powers, who would do anything they could to keep that state as permanent as possible. That's two. The vast majority of any victims of such riots, if they were to spill over the entire country, would be white people, since they would be simply too intimidated by the political climate to act decisively. That's three.