WASHINGTON - Sporadic complaints about voting procedures surfaced from Pennsylvania to Florida on Tuesday, while long lines in many states posed their own challenges in what could be one of the closest presidential elections in US history.

Watchdog groups said there was confusion over voter ID requirements in Pennsylvania, a state Obama had been expected to win, but that Romney visited in recent days as he sought to expand the battleground.

"Poll workers have been poorly and wrongfully trained, and they are standing there and sitting there and requiring people to show ID, and sending people home if they don't have the ID," said Barbara Arnwine, executive director of the Lawyers' Committee for Civil Rights, at a press conference in Washington. "The state of Pennsylvania ought to be ashamed."

Long lines at polls in many states prompted concerns that some voters would give up without casting their ballots. Lengthy waits to vote were reported in Florida, Virginia and Ohio, all key swing states, as well as New Jersey and New York, states walloped a week ago by superstorm Sandy.

Civil rights leaders said the lines threatened to be an international embarrassment for the United States.

"When you look at the lines that have formed in places like Ohio, they are longer than the lines in Baghdad and Kabul," said Wade Henderson, president of the Leadership Conference on Civil and Human Rights.

College students voting away from home also ran into problems in Florida.

At the massive University of Central Florida in Orlando, with some 58,000 students, many students had to use provisional ballots because their voter registration cards list their home addresses. A new state law for the first time prohibits making address changes on the spot.

"Right now, it's annoying me," said Kristen Wiley, 20, a junior from Boca Raton who said she had requested, but not received, an absentee ballot from Palm Beach County. She was waiting in line for a provisional ballot, knowing it would not count unless her eligibility is later verified.

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