This is great feedback, but I'm not sure how to handle.

The idea, for registered users, is that you downvote the first U.S. Politics quote you see. Then the system starts sorting those lower. Over time, if you keep training the system, you'll never see a U.S. politics quote.

But for new users, how to handle? Right now for anonymous users I have a basic HN sorting algorithm.What you are saying is that this might not be enough. Should I leave it as is? Should I add some kind of heading or sorting on the page so that people can easily see the topics (topics appear as you mouse over the quote). Not sure.