DURHAM, N.H. — In a brutally caustic debate Thursday night, Hillary Clinton accused Sen. Bernie Sanders of conducting "attacks by insinuation and innuendo" against her integrity and her credentials as a progressive by portraying her as beholden to wealthy interests and corporations.
Clinton, lobbing her harshest assault yet in their race for the Democratic presidential nomination, said that months of criticism by Sanders over her taking speaking fees from Wall Street banks amounted to a suggestion that she was corrupt — or, as she put it, a "very artful smear," a remark that drew a chorus of boos from Sanders admirers and others in the audience here at the University of New Hampshire.
"There is this attack that he is putting out, which really comes down to, anybody who took donations or speaking fees from any interest group has to be bought," she said. "And I just absolutely reject that, Senator. And I really don't think these attacks by insinuation and innuendo are worthy of you. Enough is enough. If you've got something to say, say it directly."
Sanders largely ignored the broadside, reiterating his oft-repeated critique that a super PAC supporting Clinton is funded in part by banks.
"There is a reason why these people are putting huge amounts of money into our political system," Sanders said. "It is undermining American democracy and it is allowing Congress to represent wealthy campaign contributors and not the working families of this country."
From its opening moments, the debate devolved into a series of searing exchanges over one overarching theme: which of the two Democrats was the most progressive, an issue that they have been fighting over in recent days as they compete to win Tuesday's primary in New Hampshire. On one level, the debate was over semantics: The candidates share a similar worldview about aggressive government support for universal health care, public education and aid to the poor, and both of them used the word "rigged" to describe the U.S. economy.
But they kept putting their own personal spin on the word "progressive," with Clinton deriding Sanders as the "self-proclaimed gatekeeper for progressivism." Rebutting Sanders' claim that she is a political moderate, Clinton sought to align herself with some of the most popular names in Democratic politics to suggest that Sanders was impugning them, not just her, with what she described as a purity test.
"The root of that word, progressive, is progress, but I've heard Sen. Sanders' comments and it's really caused me to wonder who's left in the progressive wing of the Democratic Party," Clinton said. "Under his definition, President Obama is not progressive because he took donations from Wall Street. Vice President Biden is not progressive because he supported Keystone," the energy pipeline project.
"Sen. Sanders and I share some very big progressive goals," Clinton said. But after she noted that they both supported universal health care, she assailed Sanders' proposal to replace the Affordable Care Act with a Medicare-for-all single payer health plan. "I don't want to rip away the security that people finally have — 18 million people have health care," she said.
"The idea that I would dismantle health care in America while we're waiting to pass a Medicare-for-all is just not accurate," Sanders replied sharply.
Sanders, asked if President Barack Obama was a progressive, at first did not answer the question, instead bringing up a comment by Clinton when she called herself a moderate. But he ultimately took on the question.
"Do I think President Obama is a progressive? Yeah, I do," Sanders said. "I disagree with him on a number of issues, including the trade agreement, but, yes, I think he has done an excellent job."
Clinton went on the attack far more than Sanders, reflecting her determination to undercut his popularity in New Hampshire, where he leads her by 20 points, according to a new NBC News/Wall Street Journal/Marist Poll on Thursday night. But Clinton also indicated she was looking past next week's primary.
She portrayed herself as a veteran of the country's political wars who is better equipped to enact a progressive agenda than her more uncompromising rival. It was not a message likely to resonate among Sanders' idealistic young legions in New Hampshire, but it presaged the campaign she is likely to carry when the primary moves to Nevada and South Carolina, more moderate states, later this month.
Clinton sought to turn Sanders' claim that she was insufficiently liberal around, unloading a barrage of opposition research about his past votes.
"If we're going to get into labels, I don't think it was particularly progressive to vote against the Brady Bill five times," she said, referring to the gun control measure. "I don't think it was progressive to vote to give gun makers and sellers immunity. I don't think it was progressive to vote against Ted Kennedy's immigration reform."
The debate was the first to feature only Clinton and Sanders, now that former Gov. Martin O'Malley of Maryland has left the race, and the narrower aperture revealed significant differences. Clinton seemed more tense at times in their rapid-fire exchanges. Sanders, meanwhile, was able to focus tightly on the major themes of his campaign, calling for a "political revolution" and attacking the influence of money in politics. He seemed surprised at times by the level of Clinton's vitriol, but it never threw him off his central message.
"Millions of Americans are giving up on the political process, and they're giving up on the political process because they understand that the economy is rigged," he said. He zeroed in on wealthy Americans and Wall Street firms giving huge sums of money to candidates — an implicit criticism of Clinton, though he did not say her by name.
Sanders twice let opportunities go by when he could have pressed Clinton on her taking speaking fees from banks. Instead, he ignored her and presented his own well-honed lecture about what he described as a corrupt system in which the financial institutions have outsize political influence and are treated with kid gloves when they break the law.
"One of the things we should do is not only talk the talk, but walk the walk," he said. "We have raised 3.5 million individual contributions, averaging $27 dollars apiece. That is what the political revolution means."
Clinton repeatedly tried to frame Sanders as a politician who has had ambitious ideas for decades but little to show for it. "The numbers just don't add up from what Senator Sanders is proposing," Clinton said. "A progressive is someone who makes progress. That's what I intend to do."
Sanders dismissed the idea that his long record in Congress showed he was unable to enact major changes. "Well I haven't quite run for president before," he said.
For the candidates and their campaign advisers, Thursday's debate was the most consequential so far, given its potential influence on undecided primary voters who are now highly engaged in the race.
Clinton hoped to undercut Sanders in New Hampshire, where he holds a strong lead in the polls.
Yet despite Sanders' lead, she has been campaigning aggressively in the belief that her history in the state — where she won the 2008 primary and her husband thanked New Hampshire residents for making him the "comeback kid" in 1992 — gives her a reservoir of support and good will that could crest on Tuesday and carry her to victory.
Sanders has his own strong base of voters in New Hampshire after three decades in the public eye as a mayor, congressman and senator in Vermont, which shares television and newspaper media markets with the western and northern parts of this state.
While Clinton has tried to raise expectations and pressure on Sanders by saying that New Hampshire always supports neighboring politicians, that trend is mostly true of candidates from Massachusetts — a point that his advisers have made repeatedly in trying to position Mr. Sanders as the underdog.
Clinton has grown increasingly open about linking her candidacy to Obama, effectively portraying herself as seeking his third term. It is a way to defuse Sanders' attacks: The president, like Clinton, is far less of a populist on issues like trade and financial regulation than is Sanders.
But embracing Obama is also a way for Clinton to prevent erosion of her support among African-Americans, perhaps her ultimate bulwark against Sanders. While there are few black voters in New Hampshire, they represent a crucial constituency in the South Carolina primary and in other Southern contests on March 1. With Sanders raising more money than Clinton in January he has the resources to force her into a longer race unless she can seriously damage him in the South.