If they start to attack you personally, you can sit back with a satisfied sigh. You’ve won. They have nothing else to do but ad hominem attacks.
Usually I’ll point this out. I resist the urge to tell them how pathetic it is to try to argue by not talking about the subject and talking about the person, instead. No. I give in. It is pretty pathetic. I think you can say that without attacking someone personally.
But it’s funny when someone is so whipped they can’t even talk about the subject. Pointing it out is pretty effective.
You have to resist the urge to take their comments personally. I think we imagine them having their jollies and maybe even making us look bad in front of all the [imagined] others who might be watching. I think they get much more pissed on if you ignore their stupid comments and point out how what they are doing is the last resort of someone who’s got nothing to say.