Would-be voters who are turned away from the polls, told they are not registered or denied provisional ballots can call 1-866-OURVOTE, a toll-free number, for help.

"People will advise them how to deal with the problem," said Barry Kauffman of Common Cause/Pennsylvania, which is helping spread the word about the National Voter Hotline.

Another group, the nonpartisan Election Protection coalition, meanwhile, has a separate hot line manned by trained volunteers who will provide state-specific information on resolving conflicts over voter identification requirements, voting machine malfunctions and voter intimidation.

To report problems, call the national Election Day hot line at 1-866-OURVOTE. For more information, visit www.EP365.org or www.866OurVote.org.