"Maggie brings a comfort level," a Clinton campaign source told ABC News' Kate Snow. "She is a woman. She's a minority. She can talk the talk, and she understands the field operations."
Exit poll results suggested Clinton's candidacy resonated with women, especially older women.
Clinton's campaign inspired a gender gap in New Hampshire, with Clinton winning by 9 points among women voters, while Obama won men by a wide 42-30 percent margin.
Among women ages 65 and over, Clinton won 57 percent to Obama's 27 percent. In comparison, Clinton and Obama tied at 39 percent among men 65 and over.
The economy was the single biggest issue to voters, and that worked for Clinton as well. Among those who called it their top concern, she beat Obama by 9 points, 44-35 percent.
Meanwhile, Obama won the message game. Exit poll results indicate 55 percent of Democratic primary voters said they're most interested in a candidate who can bring about needed change.
Only about two in 10 say they care most about experience -- the message most touted during the campaign by Clinton.
In recent days, the New York senator had begun to retool her appeal to voters, lessening her emphasis on experience and raising questions about Obama's ability to bring about the change he promises.
Meanwhile, one quarter of the Democratic primary voters polls said Clinton "ran the most unfair campaign," while one in 10 thought it was Obama, and another one in 10 pointed the finger at Edwards.
Clinton won mainline Democrats, by 45-34 percent; Obama won independents by a wider 45-30 percent. Independents accounted for just over four in 10 New Hampshire voters, down from 48 percent in the last primary in 2004, and a high of 50 percent in 1992.
Obama pounded the pavement early Tuesday, bringing doughnuts to polling sites, shaking hands and urging New Hampshire voters to the polls.
"Today you can make your voice heard, you can insist that change will come," Obama said at a campaign rally at Dartmouth College in New Hampshire Tuesday morning. "The American people have decided for the first time in a very long time to cast aside cynicism, to cast aside fear, to cast aside doubts."
The senator from New York, who banked on New Hampshire acting as a "firewall" against an Obama surge, began the day with a difficult morning.
As the senator greeted supporters outside a polling station in Nashua, she was dissed by Edwards supporters, who yelled, "Hey, hey, ho, ho. Status quo has got to go!"
When she extended a hand to an Edwards supporter, he refused to shake the former first lady's hand. She patted him on the shoulder and moved on.
At another stop in Derry, a woman holding a Mitt Romney sign heckled Clinton outside a polling site, yelling at her to move her campaign bus.
"Voters can't get in because your bus is in the way," the woman said. Clinton said she'd have it moved.
The slights appeared to roll of Clinton's back, who became emotional yesterday when a woman asked he how she was coping in such a grueling campaign.
ABC News estimated record turnout in the New Hampshire primaries, driven by record turnout on the Democratic side.
Estimated turnout on the Democrat side is 28 percent of the eligible voting population, and on the Republican side, it's 23 percent, which means that overall turnout is estimated at about half of eligible voters.