The Democratic presidential candidates met in Charleston, South Carolina, on Sunday for their last debate before the Iowa caucuses in two weeks and with the race tighter, the exchanges were sharper. Here are some of the top moments from the NBC News/You Tube debate.
Former Secretary of State Hillary Clinton and Vermont Sen. Bernie Sanders disagreed over how to go forward, with Clinton supporting Obamacare and Sanders favoring a single-payer health care plan. Hours before the debate, he revealed the taxes he would raise to finance his single-payer health care plan.
Clinton was asked whether it was fair to say that Sanders wanted to kill Obamacare. She respected Sanders' intentions, but had questions about the nine health-care bills he has introduced over 20 years, she said.
"He didn't like that, his campaign didn't like it either and tonight he's come out with a new health-care plan," she said.
Sanders, after pointing out that she had not answered the question, said that his plan would provide health care for all as a right. He blamed a corrupt campaign system for allowing pharmaceutical and health-care companies to pour money into campaigns and thwart efforts to change the system.
Clinton said that she had stood up to the health care industry when it spent millions of dollars attacking her, and she argued for building on Obamacare rather than risk it being repealed.
The match-up took place near the Emanuel African Methodist Episcopal Church, where nine people were shot to death in the summer during Bible study. Clinton listed votes Sanders has made that she said were in line with the NRA: against the Brady Bill five times, for allowing guns on Amtrak and in national parks, among others.
She has gone after Sanders repeatedly for supporting a 2005 law granting gun manufacturers legal immunity and she did again Sunday night.
Sanders said he would back reversing the law — a change Clinton quickly called a “flip-flop.” He called Clinton "disingenuous" for claiming he was a reliable vote for the gun lobby and pointed to his lifetime rating of a D- from the NRA.
On the economy, Sanders was asked about differences between him and Clinton on regulating Wall Street. Sanders calls for breaking up big banks and closing tax loopholes.
“The first difference is I don’t take money from big banks, I don’t get personal speaking fees from Goldman Sachs,” he said.
Clinton said Sanders was criticizing not just her but also President Obama who took donations from Wall Street.
“And President Obama has led our country out of the Great Recession,” Clinton said. “Senator Sanders called him weak, disappointing, he even in 2011 publicly sought someone to run in a primary against President Obama.”
Obama also signed the Dodd-Frank Act to regulate Wall Street, she said, and she called it one of the most important regulatory schemes since the 1930s.
"So I'm going to defend Dodd-Frank and I'm going to defend President Obama for taking on Wall Street, taking on the financial industry and getting results," she said.
Sanders responded that he and Obama were friends, and that they had campaigned for each other.
"Set the record right," he said.
Former Maryland Gov. Martin O'Malley jumped in when Clinton called her plans to curb Wall Street excesses the toughest and most comprehensive.
"That's not true," he said.
O'Malley said he would put "cops back on the beat of Wall Street."
On climate change, O’Malley said that the three Democrats “actually believe in science.”
Sanders called Republicans a party so owned by the fossil fuel industry that its candidates did not have the courage to listen to the scientists.
He particularly mocked Donald Trump for once tweeting: “The concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive.”
It was his second reference to Trump. Earlier in the debate, Sanders said, "In terms of polling, guess what? We are running ahead of Secretary Clinton in terms of taking on my good friend Donald Trump."