We need to be talking about the political implications of what we've built, and figuring out how to fix our mess. This is like the period before the hurricane: everyone should be busy boarding up windows, and you can't do that if you decide you're just not going to talk about the coming storm because it makes you feel bad.
From what I have seen I don't think HN in its current form is the right forum for those discussions. Even scanning this sub-thread prompted by your comment I'm already starting to see that the discussion seems to be devolving. Here is a group of technologists that could in theory spin up another forum with moderation tools and integration with HN to have back and forth between the two forums based on what "flavor" (political or technical) the discussion was going in and all I see is second-guessing and critiquing with no actionable and constructive items in the mix.
I don't know about 'actionable items', but political conversation isn't any different than other conversations -- civility, the assumption of good faith, and an open mind are more common factors as to whether a discussion is good or bad versus topic.
The problem with political discussion isn't that it's political, it's that America (and possibly elsewhere that I can't speak to) has decided that "my side is good, the other side is bad". This leads to conversations that assume bad faith, and are close-minded, which makes those discussions "bad". You can't fix that with a set of rules, but you can enforce the same rules around those discussions -- people being rude, snarky or dismissive would be subject to censure, while people who are being courteous, informative and civil would not.
In short, I maintain that the problem with political discussions versus other discussions is that we treat them as different than other discussions. At their best, they can be a productive means of informing others to facts they may not have been aware, or elevating one's opinion from a basic understanding to a more nuanced understanding. But the more special we treat politics, the more the regular rules suffer, and blanket policies banning politics foster this special status in which vitriol becomes normalized, regimented and de rigueur.
So long as incivility is normal, the greater our partisan divides will grow.
You discuss it the same way you discuss any other idea in good faith:
by evaluating the content on its message, not on the presuppositions you might have for its messenger;
by evaluating each topic in isolation on its own, and trying to determine whether or not any individual point has merit or not, how much merit it may have, and where it does not have merit, explaining why you consider it meritless;
by being open-minded enough to not dismiss individual points because you disagree with the central thesis;
by putting forth your best arguments, and letting the stronger argument win the day, unblemished by vitriol;
by being civil and courteous to your fellow man because as humans, they're deserving of at least a civil, open minded discussion.