The polls opened and closed within 43 seconds in Dixville Notch, where Obama and Romney each received 5 votes — the first time there's been a tie in the community. In Hart's Location, Obama won with 23 votes, Romney received 9 and Libertarian Gary Johnson received 1 vote. Voting there took 5 minutes, 42 seconds.
Secretary of State William Gardner predicted 722,000 people, or 70 percent of New Hampshire's voting age population, would cast ballots. More than 808,000 people are registered, and voters also can register at the polls.
Voters also were deciding close races for two congressional seats and cast ballots for 400 state House seats and 24 state Senate seats.
In the presidential race, both sides point to 2000, when Democrat Al Gore lost New Hampshire by 7,000 popular votes to Republican George W. Bush. Had Gore prevailed in New Hampshire, he would have had the 270 electoral votes needed to win the election, and the famously disputed Florida vote would not have determined the race.
A WMUR-TV Granite State Poll released Sunday night showed Obama slightly ahead of Romney in New Hampshire. In the gubernatorial race — where Lynch's retirement is leaving an open seat for the first time in a decade — the poll showed Democrat Hassan leading Republican Lamontagne, with 12 percent undecided.
Democrat Ann McLane Kuster had a slight lead over Republican Rep. Charles Bass in the 2nd Congressional District in northern and Western New Hampshire, while Republican Rep. Frank Guinta and Democrat Carol Shea-Porter were tied in the 1st District in southeastern New Hampshire. Both races are rematches of 2010.
Both parties predict Democratic gains in the Statehouse. The number in the House is 288 Republican to 102 Democrats with 10 vacancies. There are 18 Republicans and five Democrats in the Senate, with one vacancy.
Voters also faced a lengthy ballot with two proposed constitutional amendments.
Associated Press reporter Lynne Tuohy in Newbury, N.H., contributed to this report.