Readers who recall my series, The Next American Revolution . . . will be stillborn (links for all the parts contained in post) may find it interesting that John Derbyshire has come to very similar conclusions about the future of the nation.
The Derb doesn't think sectional secession will occur and that there's a chance for the federal government to turn wholly totalitarian.
He mentions a race war scenario by Matt Bracken as far fetched. My series discusses the likelihood of riots and disorders when the money stops and considers they'll be contained better than Bracken's scenario expects.
I think break up will occur entirely due to economic reasons and will be gradual rather than formal as regions sever monetary ties with Washington by way of a separate currency and a break down of federal ability to collect taxes.
Derb's take is a sober and interesting look at the future, though.