I went to one of the large Obama rallies in the waning days of the election. It was an incredible gathering of diversity, like a peace rally without pot. A few things were evident. Obama's is a youth movement. For them, he has the air of a movie star or musician. He speaks to them of justice and power. The crowd consisted of approximately equal proportions of white and non-white, male and female. It was overwhelmingly working class. And it was overwhelmingly anti-Bush.
I could not find a McCain rally to attend, but I managed to find a Sarah Palin event. It was much different. It was overwhelmingly white, and people stood in a long line to enter the building in which the rally was held. It was a bit like waiting for a ride at Disneyworld.