As I said, insults are not ad hominem in and of themselves.
Not ad hominem, not trying to refute the argument, but still an insult.
"He's an asshole, and his argument is crap."
Not ad hominem, refuting the argument by mere assertion, and an insult.
"He's an asshole, so his argument can't be taken seriously."
Ad hominem - implying that some characteristic of the person makes his argument flawed; and an insult.
"He just wants what's best for his daughter, so his argument can't be taken seriously."
Ad hominem (implying bias); but not an insult.
While I can, in fact, guess why he concluded that, I am merely guessing because his reasoning was not explained very well.
I really hope that I'm wrong in believing that about half of his problems are with the use of political labels. The very meaning of all political labels is contested: people abuse them constantly for their own purposes, so they do not carry the same meaning for all people. For example, "socialism" can be anything from an oppressive government that ruthlessly punishes success to neighbors banding together to help each other out in times of trouble. Or it can be used as a simple insult.
The problem isn't that these words have no meaning, the problem is that people are fighting over what these words should mean. As Lewis Carroll put it, 'The question is,' said Humpty Dumpty, 'which is to be master -- that's all.'
If you're so much cleverer than this chap, why have you not felt it necessary to accompany your ad-hominem attacks with at least a basic level of elucidation?
To the chap in question: insightful views clearly stated. I applaud your goals and I hope we can make it happen.