It really bothers me that politicians would use this kind of language. It's not exactly a lie but it is completely misleading. African American Trayvon Martin jumped a Hispanic guy, started bashing his head into cement and then the guy successfully saved himself through justified self-defense. To equate that to "White Supremacy" is awful.
Consider what is being proposed as an alternative to "white supremacy". It is not equality under the law. That has been rejected. To the Left, a "colorblind society" is racist.
What they are aiming for is black supremacy.
If there had been effective black supremacy, George Zimmerman would not have been allowed a firearm, and he would be dead, not Trayvon Martin.