If a brown looking hispanic has a white last name or a white looking person a hispanic last name they become a "white hispanic". This makes it easier to compartmentalize a stereotype.
George Zimmerman has a white father and a hispanic mother therefore he is a "White Hispanic". Even though he looks more hispanic his last name is white and it becomes more polarizing to play up his whiteness.
George Zimmerman kills Trayvon Martin. - "That honky George Zimmerman killed Trayvon for wearing a hoody."