I didn't think Osama was this stupid. Everything he said in that tape helps Bush. I doubt he wants Bush to win because he helped put the leftist party in power in Spain and unsuccessfully tried to get John Howard's party out.
Left, right, doesn't make a lick of difference to religious totalitarians. More important is to split the US from allies. And playing to their natural left tendancies and our natural right tendancies is the obvious way to do that.