When someone throws a punch at you (negative ad) you say it is negative when you punch back you? I have to disagree.
It’s not really a matter of being “negative” - but rather, first of all, it seems unnecessary - Bush is way down the list in most polls - Trump has several people who are more an immediate threat to him including Cruz and Rubio whom it would seem he should really be concentrating on - also, his responses are not directed to the issues or policies but are personal - “He’s a loser” and “he’s a low energy person” are the sorts of things I would expect to hear on a school playground, not in a serious political debate....