I see there is some chiseling away at FedGov over-reach, say gun control or Obamacare, in the state legislators. But that seems like it will all be sorted out in the Federal Courts, not on the court house green with bayonets.
It's still a far cry from declaring independence and secession.
So, if we are going to have a civil war it's going to be along some other lines - fact it almost every state in the Union has some huge areas of Blue infestation. Archy has suggested that the model might be more like the Argentinian and Chillean "Dirty Wars". That is an undercover war of ideologically aligned groups contending with one another, perhaps one faction fighting from a position of power. In the case of Chile and Argentina it was the right which held power and used the military, police and para-military groups to fight the Communist menace.
Here, I could see it going the opposite way. Obama declares a state of emergency and begins ruling by decree, while Holder and Napalitino bring their troops together (who will have been ideologically cleansed by then into a pure far-left shock force) and use them to round up rightwing dissidents using Bush-era anti-terrorism laws.
I really have trouble imagining the right doing the same thing here. The right has too much investment in the old values of honor, fidelity and adherence to the Constitution to run purges from the government. That suggests to me that if there is an insurgency from the right it will be a multi-faceted one, sort of a rising up of the Tea Parties. But the right will openly declare their intentions, as the founders did, out of a sense of obligation to the ideals of the founders.
Of course a third, and perhaps most likely scenario, one already suggested by another poster on this thread would be a breakdown and riots leading to a violent racial conflict. We saw the first glimmers of that in LA during the Rodney King riots where the Korean store owners shot at the rampaging rioters, who were mostly black and Mexican.
The last time we had a "long hot summer", in 67 and 68 the National Guard was able to restore order, and the black rioters only burnt up their own neighborhoods. It seems likely things would spread more this time, and whether or not the NatGuard would be available to put down a riot is unclear. I believe most of Oregon's has been deployed for years now in Iraq and Afghanistan. If you do get the NG, well it's a whole different force than the boys of 1967, many of whom were staying out of Vietnam by being in the Guard.
Nowadays the Guard is full of experienced battle-hardened vets.
Now, looking at these scenarios I say on a scale of 1 to 5 -where 1 is very unlikely and 5 is very likely that Scenario 1: leftist led dirty war is about a "2", Scenario 2: Tea Party uprising is probably a "1", and race riots leading to a larger conflagration is, perhaps a "3".
In other words, any real CWII is still unlikely, but it is moving in the direction of more likely over time.
Makes me glad to have left SoCal for Fl a few years back.