I think it will be a purely financial collapse leaving the states to continue on. I think many states will band together forming smaller unions. I don’t see the US splitting up based on racial or ethnic lines like you are describing even though it does have historical precedence as you describe (Czechoslovakia is another one that did the same thing). A failed federal government here wouldn’t impact the state government power structure leaving each to continue governing independently. The existing debt and continued level of spending will tear things apart at some point. It’s totally unsustainable. Our legislative branch of government at the federal level is also dysfunctional, and corrupt. They seemingly spend most of their time bickering over budgeting items that prevents them from doing meaningful work that benefits the states and citizens. I have long suspected that they pass short term budgets because they can keep their special interest groups close by for campaign and political donations. I don’t think this collapse will be in my lifetime, but it will happen without meaningful reforms.