If you believe recent polls, approximately 48% of likely voters are voicing support for Bush. As all say, it will be tight.
It's fair to assert that the President is the most powerful position in the world, evidenced by the coercion of Bush towards the world, despite his imperialist approach and resultant immense unpopularity amongst most of planet's peoples.
Standing back, it is incredible that such a relative few can potentially decide the destiny of the remainder of the world's population. Assuming that approximately 50% of voters will determine the President this year (perhaps 57 - 62 million people) and a world population of 6.397 billion, it's possible that voting GOPers, representing 0.95% of the planet's population, could tell the rest of the world to go straight to Hell!