It’s a culture clash of a primal kind. Settlers and nomads. Cops and robbers. Builders and destroyers. And it was never going to end well. The elites want the settlers to make way for the nomads, the cops to acknowledge their role in alienating the robbers and the builders to admit that their construction is really the destruction of the way of life of the destroyers. They don’t understand the struggling lower middle class and they don’t care to. They have a great deal of empathy for the Trayvon Martins swaggering around another neighborhood that decays at their touch, but none for the George Zimmermans, sweating, mopping their brows, worrying how they’re going to hold everything together. 
Neighborhood watches don’t have to turn violent, but they exist because of the potential for violence in a society with plenty of law, but little order. The struggling middle class looks to the cops only to realize that the cops have their own job and it isn’t to protect them, it’s to protect each other. And so they become cops. It’s vigilantism of a sort and it’s a symptom of social collapse. But it’s also the attitude that helped make the United States happen.
That’s the real story behind the headlines, the agitprop and the circus of a public trial. It’s the reality that doesn’t get talked about much because it’s much less interesting than the straightforward story being fed into the presses. The one about an innocent young boy killed for no reason at all. It’s a story about what happens when people are backed into a corner and then told to stay there. It’s about a frightened middle class trying to survive. And it’s about territory.
Settlers make homes. Nomads walk in and out of them. Builders thrive on making things and destroyers on trashing them. Zimmerman picked his side of the coin and Martin picked his.