You want to hang it on race? Nah. Try age.
He got the youth vote. They are behind him. He has their energy. Look for him to use it.
You can also look to McCain's age, and his running mate. Talking to a quintessential white male at work yesterday, he said, "I never had a strong positive feeling about either of the candidates, but one of them picked a strong reason for me to vote against him."