there's http://www.washingtonpost.com/blogs/ezra-klein/wp/2012/10/23/how-to-manipulate-prediction-markets-and-boost-mitt-romneys-fortunes/ http://www.washington

there's http://www.washingtonpost.com/blogs/ezra-klein/wp/2012/10/23/how-to-manipulate-prediction-markets-and-boost-mitt-romneys-fortunes/ http://www.washingtonpost.com/blogs/ezra-klein/wp/2012/10/23... which was mentioned at http://fivethirtyeight.blogs.nytimes.com/2012/10/24/oct-23-the-virtues-and-vices-of-election-prediction-markets/ http://fivethirtyeight.blogs.nytimes.com/2012/10/24/oct-23-t... chart in first link shows large romney buyer. not sure if that's what you're looking for with "statistical smoking gun" though. a little more analysis at second link.