It was similar. Users flagged many posts, and we applied the same principles as I've described in this thread, as best we could. That involved turning off flags on certain stories. Unfortunately, the threads did not go well.

That experience is one reason why I'm taking a different approach in the current thread. We're trying to learn over time how to support some discussion (but not too much) of these difficult topics, while remaining within the intended spirit of the site.

Could these threads be saved by a different post weighting model? Throw away downvoted posts, but also discard controversial up voted posts? Or detect bipartisan voting and discard those votes?

I do think there's room to experiment with that, yes.