Here is a good USA Today article that provides a bit of background about how this works: http://www.usatoday.com/news/politics/story/2012-08-01/twitter-politic

Here is a good USA Today article that provides a bit of background about how this works: http://www.usatoday.com/news/politics/story/2012-08-01/twitter-political-index/56649678/1#.UBlRNwVSz4I.twitter http://www.usatoday.com/news/politics/story/2012-08-01/twitt... I was very surprised to read in the article that: "The Twitterverse isn't particularly politically biased, say the Republican and Democratic pollsters who worked on the project, because while Twitter users overall may be younger and therefore more likely to support Obama, conservative tweeters tend to be more active."