Intrade is not that good in non political elections.In political elections I wouldnt bet against them A few examples Bush /Kerry Obama /McCain 2008 House 2008 Senate 2010 House(From July until election day they had Republicans taking the House over 50) Wisconsin recall( Had Walker over 50 the life of the contract)
http://money.cnn.com/2012/09/14/investing/obama-election-intrade/?google_editors_picks=true Intrade: Fed helped Obama's re-election odds