Five days after finishing a disappointing third in Iowa, the former first lady trails Obama by double digits in many New Hampshire polls and had to reassure supporters on Monday that she was staying in the race.
For Obama, a US senator from Illinois bidding to be the first black president, a win in New Hampshire would solidify his hold on the top spot in the Democratic nominating campaign.
In a hard-fought Republican battle, Sen John McCain of Arizona holds a narrow lead over Mitt Romney, the former governor of neighboring Massachusetts who poured tens of millions of his personal wealth into the race. Clinton and Romney are both under heavy pressure to revive their campaigns after disappointing showings in Iowa. Until recently, Romney led polls in Iowa and New Hampshire, but he finished second in Iowa to former Arkansas governor Mike Huckabee. A new Reuters/C-SPAN/Zogby poll showed Obama expanding his lead over Clinton to 13 points, 42 per cent to 29 per cent, with former North Carolina senator John Edwards in third at 17 per cent.
Polls close at 8 pm EST (0100 GMT Wednesday) on Tuesday, with results expected to begin rolling in quickly.
State election officials have predicted a record turnout in New Hampshire during the most wide open US presidential race in more than 50 years, with no sitting president or vice president seeking the nominations. The tiny mountain hamlet of Dixville Notch opened the state’s voting shortly after midnight, as it has for every election since 1960, in a balloting display more media circus than civic event.
A few of the town's registered voters cast ballots. Obama won seven of the 10 Democratic votes, Edwards getting two and Richardson getting one. McCain won four of the seven Republican votes, with Romney winning two and former New York Mayor Rudy Giuliani getting one. In the final hours of the state’s campaign on Monday, the candidates sought to drive home their message and fire up supporters to turn out. Clinton closed the day with a final rally in Manchester with her husband, former president Bill Clinton. She said she would stay in the race until “Super Tuesday” on February 5.