Political Futures (navel gazing)

It's interesting that as of  10:00 this morning, you can buy at Intrade (I'm not sure if US citizens can) the chance that the Democratic nominee will be elected President for $5.12 and sell the chance that Obama will be re-elected for $5.16.  This would guarantee an arbitrage profit of $0.04 or about 0.8% which would be huge in the finance world.