If Obama had not opened his mouth and injected himself in the Martin matter, who knows how it would have played out. But we are left with that fact, a sort of precedent that has yielded a race violence score card that many will now keep. Let's see, off hand since the Martin verdict we had the thee black kids beat up a white kid on a bus, the Duncan shooting, and the 88 year old vet murder. Of those three white decedents, how many were on top of their assailant raining down punches before their death? Better yet, how many of them even had a chance to fight or even flee?
Just my $.02, it's the perceived racism in the Martin/Zimmerman, that Martin was targeted for the confrontation because of his color. The others are perceived as just crimes of opportunity, and the speculation that Lanes murder/13 year old on the bus/elderly Veteran was a gang initiation/shooter was bored/bad parenting/actually hates whites is viewed by the talking heads as "Have pity on these underserved/underprivileged/poor misguided children.