Just because they voted for Obama doesn’t make them not racist. Plenty of people are racist and associate and are friendly with people of color, listen to black musicians, watch sports with black athletes, and watch TV or films with black characters, sometimes even ones that are primarily starring black casts.
Racism is not just hating black people, it’s supporting structures that privilege white people over others, believing in whiteness and understanding human beings primarily by their race and assuming that they have the racist characteristics of that racial stereotype.