I think it is reasonable to avoid political subjects that are off topic. Which is difficult, I know, because on-topic for HN is literally 'Anything that good hackers would find interesting.'
Perhaps, for politics, it would be good to try to limit political discussion to things that affect the technology world broadly, and startups specifically?
In the past, topics like those have been discussed here quite productively. Since the U.S. election, I've noticed posts getting flagged that seemed like they were worthy of discussion. I'm not sure if the flagging was ideologically motivated, or if it just happened because of election fatigue.
Even though I don't live in the U.S., I still like to see these discussions happen because the impacts of things that happen tend to have repercussions throughout the tech world.
Maybe limiting comments on political topics to people with 500+ or karma would make reasonable discussion more likely? It's not insanely difficult to react that level in a month or two if you're making thoughtful contributions to the community.