Hillary Clinton laid into her Democratic challenger, accusing Bernie Sanders of trying unfairly to hog a progressive mantle but admitting she had work to do to win over young voters.
"I am a progressive who gets results and I will be a progressive president who gets results," she told a town hall meeting in Derry, New Hampshire, where she is fighting against Sanders' dominance in local polls ahead of next week's state primary, the second contest in the 2016 race for the White House.
"I was somewhat amused today to hear Senator Sanders set himself up as the gatekeeper for the definition of what's progressive," she said during the event moderated by television news network CNN.
"I don't think it helps for the senator to be making those kind of comparisons because clearly we all share a lot of the same hopes and aspirations for our country."
A relaxed and confident former secretary of state answered questions from voters after clinching the narrowest win in Iowa caucus history with 49.8 percent compared to 49.6 percent for Sanders.
Disconcerting for Clinton in the first test of the lengthy presidential campaign was Sanders's crushing victory among Democratic voters aged 17 to 29, who gave him 84 percent of their support.
"That's amazing," she said when asked by CNN about Sanders' majority backing among young people in Iowa.
"I accept the fact that I have work to do to convey what I stand for, what I've accomplished, what I want to do for young people in our country," she said.
"They don't have to be for me, I'm going to be for them," she added to warm applause.
Her challenger told the town hall that he respected Clinton for her "long and distinguished career" but insisted: "I think there are issues where she just is not progressive."
The senator from Vermont has inspired a passionate following among young voters with his Scandinavian-inspired anti-Wall Street, poverty busting, democratic socialist agenda.
Sanders said Clinton had taken $15 million from Wall Street, voted for the 2003 Iraq invasion and supported trade policies with China that had cost American jobs.
"That's just not progressive," he said. "You can't be a moderate and a progressive, they are different."
While Sanders' surge of support has taken some by surprise, analysts expect Clinton to still clinch the Democratic nomination not least thanks to her greater support among African Americans and Latinos.
"I think we are gaining more and more support in those communities," said Sanders when asked how he could better engage a broader electorate.
"There will be no president who will fight harder to end institutional racism than I will and we have got to reform a very, very broken criminal justice system," he added.