a personal attack, true, but it is a personal attack used as a means of discrediting an argument

a type of logical fallacy that involves replying to an argument or assertion by addressing the person presenting the argument or assertion rather than the argument itself

Attacking another personís argument by attacking the person rather than the issue. In the political arena this is called "mudslinging." example- "I disliked going to see Dr. Hopper. In fact, I probably dislike Dr. Hopper. He has a sharp nose that points downward, seeming always to be calling attention to his shoes. He is a hard faced man who who makes much of small things." Anne F. Rosner "Prize Tomatoes" "Let me say, incidentally, my opponent, my opposite number for the vice-presidency on the democratic ticket, does have his wife on the payroll, and has had her on the payroll for the last ten years." Richard Nixon