This radial diagram produced by The New York Times represents the frequency of names used by major presidential candidates in the series of Democratic and Republican debates leading up to the Iowa caucuses. Each line represents one candidate speaking the last name of another candidate. Every line ends at an arrow, which points to the name that was spoken.
The length of each circle segment represents the total number of words spoken by the candidate during the debates. Each tick mark represents 1,000 words. Each slice represents one debate, arranged clockwise from the first to the final debate.
It's also worth taking a look at an interesting treemap visualization analyzing the entire Republican Debate transcript, from November 28th, 2007.