As we've mentioned a few times before, examining which links people click on when they search for topics in the news tells us a lot about what people of different political stripes find interesting. By filtering down to search queries that reliably lead to publications with a documented political slant, we can quickly expose the conspiratorial fringe of political news.

Our friends at Yahoo! Labs Barcelona have now expanded this process into a visualization that divides these partisan searches by subject. The size of the bubbles is proportional to the percentage of all search trends for one side or the other devoted to the given topic area. It is powered by Political Search Trends, a tool that is the output of collaboration between Yahoo! Labs Barcelona and the University of Amsterdam's Digital Methods Initiative.

If you're dubious about whether this method of sorting news items works, just look at the proportions. Left-leaning sites dominate the search results for "Taxes & Spending," thanks largely to discussion of former Gov. Mitt Romney's unreleased tax returns, while right-leaning sites are more concerned with health care, one of the main lines of attack on President Barack Obama.

Mouse over any pair of bubbles to see the associated search terms.