FOX News and the entire rightwing media-scape has been crucifying the kid, making him the symbol of the great black demon that drove whites from the cities to suburbia starting in the 50s.
I remember when the Reagan Revolution was creating the ideological basis for unwinding the welfare state. Part of their mission was to frame blacks as animals, pimps, drug dealers, sub-human atavistic lazy violent gang bangers, welfare queens, takers. Much of this grew quite naturally out of the "Southern Strategy", which was a political device used to flip the "Solid South" by instigating white backlash over the Civil Rights Act. And then they created the War on Drugs which proved to be a kind of conveyor built that moved blacks from welfare to cages (prison).
While many Republicans have evolved away from racism, the Right still gives a home to people who believe that whites are the advanced, more evolved race. So whenever there is a crime involving a black person, it's very predictable what their response will be.
Is Zimmerman guilty? I honestly don't know. He was told not to pursue the kid, but he ignored that. He seemed to determine to confront this kid, either out of fear or anger. We will probably never know what really happened because the problem of race - on both sides of the aise - will suck all the air out of the room.