You're forgetting the Dem's reserve storm troopers: the Bloods and the Crips. I remember the gang summit that was organized in 1993, and how Clinton sent an address to them that was read in "closed session". I always wondered what Clinton said.
Expect the next civil war to start out as widespread inner-city riots
We've had those before but it didn't lead to civil war. The National Guard is mobilized, the riots are put down, ghetto businesses are destroyed, the ash is swept up and we get on with life. Why would another set of riots be any different?
Civil Wars are political events. Riots are emotional events and basically shopping sprees for the underclass. The underclass isn't smart enough to forment a civil war, at least ours isn't. Riots will have potential to be that when you see actual symbols of power (not police) being systematically destroyed. As long as rioters only want TV sets its not the start of anything.
The 'black block' while tiny, is overtly political. But almost no one, even on the left, agrees with them. Also, they are so confused that think Starbucks is a symbol of something.
In summary I don't believe either the (mostly black) underclass nor the far left anarchists have the ability to start anything more than a LA-style riot. That's plenty bad, but it's not a step towards civil war.