Ad hominem argument/attack :

Ad hominem argumen/attack: A personal attack on the character or other traits of one's opponent rather that an argument agains his or her ideas.

Example: 
" Not everyone, however, was so supportive. One woman, whose rolls of fat under her tight white suit made her look like a yeast bread in the bowl, waddled over to Sylvia and said, "Stick with your own kind, girl. Mixing the races will only get you hurt. They don't want you there. You hear?"

This is an attack agains the lady because the girl was not focusing on the problem. She was more worried about they way the lady looked instead of worrying about herself.