You're conflating two different things: actual political discussions and meta-political discussions focusing on e.g. "rational defenses" when it comes to politics. You're justifying the latter, but people downvote and shun the former.

The latter, in theory, could be done without any content from the former, although frequently people fail to pull that off. E.g. you could have a discussion about how and why political discussions tend to fail at rationality, and what could be done about it, without opining on any political issue. Such a discussion, I conjecture, would not attract the usual "political" downvotes and objections.