Remember the purpose of negative advertising

politicalprof:

is NOT to get you to change your vote. It’s to get you to throw up your hands and not vote in the first place.

If you like candidate A and I make you feel bad about candidate A, you don’t vote for me, candidate B. But if I can get you to not vote, that’s one less candidate A vote I have to overcome to win.

Not voting because it makes you feel better makes it just that much easier to win for the candidate whose policies you don’t like.