Abortion can be categorized as a medical issue, I suppose. And perhaps even polling data or accuracy can be thrown in as statistics. This is a fuzzy line, which is compounded by the notion that members of political parties generally argue that their view is fact rather than opinion.
When you consider HN submission rules, it does indicate "more than just hacking or startups" and things that "gratify intellectual curiosity" are in, but also that politics is generally off-topic. On a topic like this that toes the line, you probably should assume it's further off-topic than on.
The very nature of an article that is about how to talk to someone with an opposing viewpoint isn't satisfying an intellectual curiosity, but positioning someone to persuade others. Whether you phrase it as "connecting with an audience" or not, it's inherently about an argument, and how to win it.
I would argue that a discussion of new facts or research uncovered about climate change is a submission about science, and anything specifically about "climate change deniers" is politics, or at best, "argument".