Mr. Sanders, who largely kept his cool in the debate, ignored the broadside and instead reiterated his familiar critique that a "super PAC" supporting Mrs. Clinton is funded in part by banks.
More from The New York Times:
Philippe Dauman Succeeds Sumner Redstone as Viacom Chairman
Deal Shows Investors Are Willing to Make a Blind Bet on Uber
Seeing a Business Opportunity for Firms' Outside Overseers
"There is a reason why these people are putting huge amounts of money into our political system," Mr. 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."
The ferocity of Mrs. Clinton's remarks in the debate was risky, given that many voters, including some Democrats, already have an unfavorable opinion of her. She is also running far behind Mr. Sanders in the polls leading up to Tuesday's primary in New Hampshire, and her attacks — while geared toward undercutting his popularity here — might backfire with some undecided voters who have positive feelings about Mr. Sanders.
Mrs. Clinton, appearing tense and even angry at times, was particularly sensitive about receiving millions of dollars in speaking fees, including $675,000 for three speeches from Goldman Sachs. She downplayed her turn on the lecture circuit, noting that she had also addressed other groups such as the American Camping Association and that the banks merely wanted to hear her views on world affairs.
But she did acknowledge that she had not "done the job I should in explaining my record" about financial regulation, suggesting that is why she had been unable to beat back questions about her speaking fees. Yet when asked if she would release all the transcripts of her speeches to banks, she hedged.
"I will look into it," she said. "I don't know the status, but I will certainly look into it."
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 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 American economy.