He's got money to burn for the cause. Don't forget he threw Tens of millions to MoveON during the last election. He probably made Billions trading Oil over the last couple of years.
You're right. For him a few million is chump change. And I suppose even he needs a hobby and some amnusement - what better than funding a bash-America media party. I suppose it's a little like playing the futures market -- you can turn a buy-low commodity like sow bellied hogs into a surprise and even make money on a short market.