Is there an online politics and policy forum that for its topics matches the quality that HN achieves on technical topics (or does better)? Specifically, I mean the knowledge value of comments, the expertise and sophistication, and the lack of flaming and trolling.

I have yet to find one with a signal to noise ratio that is even nearly worth my time. Most are filled with misinformation, partisan spin, and propaganda attacks, none of which I learn much about (except what the latest misinfo, spin, and propaganda is). I want a forum that's focused on informing its members.