http://news.ycombinator.com/item?id=2402027
politics? I don't think so. Economic inequality is a very interesting social phenomenon, though it is often written about in a heated/political way.
maybe ensuring the articles are at least a week old, that instantly removes 99% of the current events which are generally irrelevant and if it is relevant it will still be so in a week.
You might want to consider just shutting it down for 2 months, the great users will likely come back. It will definitely lower the dunbar number quite a bit.