In New York City, where Obama has waged a block-by-block fight reaching out to African American supporters and liberal voters in Brooklyn, Queens and parts of Manhattan, some complaints surfaced of polling place problems.

"I have personally gotten some calls in regard to some Brooklyn polling sites," said Valerie Vazquez, director of communications for the city board of elections. "However, once we sent out our polling site monitors and technicians, they realized some of it is either voter error or poll worker error, not necessarily any breakdown in the machines. So these problems are quickly remedied."