1) Two wrongs don't make a right.
They don’t, but they make the wrong (which is really more a counterreaction than a "wrong") that follows the first wrong a lot more understandable.
2) I don't recall Democrats doing this excessively in polling threads or topics completely unrelated, though I could be wrong.
Less so there than on boards like U.S. General Discussion, but I and most other Republican/conservative-leaning posters definitely recall things very differently. It’s funny how differently we can "recall" things based on our partisan/ideological preferences, isn’t it?
3) Many of the red avatars who do this or refuse to engage in debate are rightfully called out for it.
No, they aren’t? In fact, some of them are some of the most "respected" forum members. It’s not just red avatars, by the way — there are "green" and Socialist avatars have been more unpleasant and combative than even most partisan red avatars, and yes, I’m not oblivious to confrontational right-of-center posters either. I also don’t want to lump all liberals (I prefer that term to "red avatars") together, but the problem is that the minority of extremely aggressive/combative posters is a large and very vocal one that thinks it can get away with anything because it is part of the majority and ~80% of moderators are Democrats.
It could be the case that the overall lean on this forum means that red avatars get away with more, but the solution to this is collectively holding them to a higher standard, not holder conservative-leaning posters to a lower standard.
Yes, but the problem is that "collectively holding them to a higher standard" never materializes. One good first step (that would probably also do most of the work) would be to create a more civil atmosphere in which personal attacks, grudges, personality cults, etc. (e.g. "Opinion of user xyz?" threads or general references to other posters) are discouraged or disallowed, but there is absolutely no indication that the majority of forum moderators has any interest in doing that.
I normally don’t insert myself in these personal fights/attacks, especially since (a) it’s largely a waste of time and (b) it’s useful fodder for certain moderators who have always held a grudge against you and are desperately looking for reasons to ban you, but again - it always helps imagining yourself in the shoes of the other side while browsing this forum and posting something. You’ve been here for years, so you really shouldn’t be surprised by the reactions of the more right-leaning posters.