I think that we (here) tend to view any potential of any revolution as coming from the right (conservative Constitutional restoration). I think that while possible, is pretty much the least likely scenario that could touch off any revolution.
I think that it is far more likely that the spark that would come from a different direction.
I think much of this is contingent on the economy and a potential bankruptcy of the fed gov.
As mentioned our creditors rushing to cash in debt and not accepting dollars as payment. A worthless currrency and massive inflation could result.
A general shut down of gov services could easily lead to a gov dependant class revolt. Without government provided, food shelter, cash payments, welfare, food stamps etc.. Panic, rioting, looting could result on a large scale.
It could be a balkanization/ breakdown situation where predominantly latino communities essentially secede (Tx, Az, Ca), as well as places like Deerborn/ Minnesota establishing communities attempting to institute Sharia law. Or similar separatist communities, trying to break away.
It could also come from something like a serious pandemic, leading gov to quarantie and contain large areas. Revolt could occur within and without the quarantine zones leading to essentially a hysterical situation of citizens vs. gov troops..
So, Generally, I see things right now as one huge powder keg that were all sitting on with fuzes running in all directions. The whole country, economy/ currency, and government are all based on faith, trust and shared ideals. Once that veil is pierced who knows what will happen.