Charleston, South Carolina (CNN) Bernie Sanders is mad as hell -- and he's hoping Democratic voters are, too.

The Vermont senator denounced a "corrupt" political system and cast himself as a break from it, while Hillary Clinton tied herself tightly with President Barack Obama and argued she'd build on his legacy, as the Democratic presidential contenders clashed Sunday night in Charleston.

Martin O'Malley delivered a dig at the GOP candidates, recounting a voter asking him to not refer to her son, who serves in the military, as a pair of boots on the ground. O'Malley said Republicans use, "boots on the ground," when they're "trying to look all bravado and macho sending other peoples' kids into combat."

Martin O'Malley delivered a dig at the GOP candidates, recounting a voter asking him to not refer to her son, who serves in the military, as a pair of boots on the ground. O'Malley said Republicans use, "boots on the ground," when they're "trying to look all bravado and macho sending other peoples' kids into combat."

A new NBC/Wall Street Journal national poll on Sunday showed Clinton leading Sanders 59% to 34%, with the third candidate in the race, former Maryland Gov. Martin O'Malley, at 2%.

A new NBC/Wall Street Journal national poll on Sunday showed Clinton leading Sanders 59% to 34%, with the third candidate in the race, former Maryland Gov. Martin O'Malley, at 2%.

Sanders angrily rejected Clinton's claims that his plans would result in the gutting of Obamacare, saying that he wanted to build on the achievements of the current president, not overturn them. "No one is tearing this up, we are going to go forward," Sanders said, his voice rising in anger. "That is nonsense."

Sanders angrily rejected Clinton's claims that his plans would result in the gutting of Obamacare, saying that he wanted to build on the achievements of the current president, not overturn them. "No one is tearing this up, we are going to go forward," Sanders said, his voice rising in anger. "That is nonsense."

Clinton and Sanders also argued over health care. "We finally have a path to universal health care, we have accomplished so much already. I do not want to see the Republicans repeal it and I don't want us to start all over again with a contentious debate," said Clinton.

Clinton and Sanders also argued over health care. "We finally have a path to universal health care, we have accomplished so much already. I do not want to see the Republicans repeal it and I don't want us to start all over again with a contentious debate," said Clinton.

Clinton and Sanders began the evening trading barbs on gun control. Clinton slammed Sanders for voting "with the NRA, with the gun lobby numerous times." Sanders hit back, arguing that he had a D-minus voting rating from the National Rifle Association and rejected her list of charges.

Clinton and Sanders began the evening trading barbs on gun control. Clinton slammed Sanders for voting "with the NRA, with the gun lobby numerous times." Sanders hit back, arguing that he had a D-minus voting rating from the National Rifle Association and rejected her list of charges.

Candidates Martin O'Malley, Hillary Clinton and Bernie Sanders take part in t he final Democratic presidential debate before the caucuses.

Candidates Martin O'Malley, Hillary Clinton and Bernie Sanders take part in t he final Democratic presidential debate before the caucuses.

Here are six takeaways from the final Democratic debate before the first votes are cast in Iowa and New Hampshire:

Sanders = Trump

It's not often you hear Sanders say the words "my good friend Donald Trump" -- but the two have something in common: Their tones match a moment of anger within the electorate.

Clinton promised continuity. She highlighted her record. She touted her ability to get results within the limitations of the modern political climate.

Sanders offered none of that. Like Trump, his cause is change, not compromise.

Photos: The many facial expressions of Donald Trump Photos: The many facial expressions of Donald Trump Many people on the Internet decided that GOP candidate Donald Trump is the most expressive person running for president. Here's a look at his many facial expressions: Hide Caption 1 of 14 Photos: The many facial expressions of Donald Trump Trump speaks about illegal immigration July 10 at the Beverly Wilshire Hotel in Beverly Hills, California. Hide Caption 2 of 14 Photos: The many facial expressions of Donald Trump Trump speaks to guests gathered for a campaign event at the Grand River Center in Dubuque, Iowa, on August 25. Hide Caption 3 of 14 Photos: The many facial expressions of Donald Trump Trump visits his Scottish golf course Turnberry on July 30. Hide Caption 4 of 14 Photos: The many facial expressions of Donald Trump Trump speaks during a rally August 21 at Ladd-Peebles Stadium in Mobile, Alabama. Hide Caption 5 of 14 Photos: The many facial expressions of Donald Trump Trump eats a pork chop on a stick while attending the Iowa State Fair on August 15. Hide Caption 6 of 14 Photos: The many facial expressions of Donald Trump Trump flashes a thumbs-up as he arrives for the start of the first presidential debate August 6 in Cleveland. Hide Caption 7 of 14 Photos: The many facial expressions of Donald Trump Trump participates in the Republican debate in Cleveland. Hide Caption 8 of 14 Photos: The many facial expressions of Donald Trump Trump arrives for jury duty in New York on August 17. Hide Caption 9 of 14 Photos: The many facial expressions of Donald Trump Trump walks his Turnberry golf course on July 30. Hide Caption 10 of 14 Photos: The many facial expressions of Donald Trump Trump at Turnberry on July 30. Hide Caption 11 of 14 Photos: The many facial expressions of Donald Trump Trump talks to the media in Laredo, Texas, during a trip to the Mexico border on July 23. Hide Caption 12 of 14 Photos: The many facial expressions of Donald Trump Trump greets onlookers after taping an interview with Anderson Cooper at a Trump-owned building in New York on July 22. Hide Caption 13 of 14 Photos: The many facial expressions of Donald Trump Trump exits New York Supreme Court after jury duty on August 17. Hide Caption 14 of 14

His take on why his Medicare-for-all proposal can't pass in Congress could have been applied to just about any of his arguments: "It's because we have a campaign finance system that is corrupt. We have super PACs. We have the pharmaceutical industry pouring hundreds of millions of dollars into campaign contributions and lobbying and the private insurance companies as well."

Sanders' fire-and-brimstone touches on some of the same topics as the Republican front-runner -- particularly super PACs and the influence of money.

Just like Trump, Sanders even riffed on polling when asked about his strategy to win over African-American voters, arguing that they'll like him more once he wins in Iowa and New Hampshire.

"Let me talk about polling. ... In terms of polling, guess what, we are running ahead of Secretary Clinton in terms of taking on my good friend Donald Trump," Sanders said. "We have the momentum. We're on a path to a victory."

Clinton = Obama

It was her go-to move, and she went to it a lot: On gun control, health care, financial regulation, her "many hours in the Situation Room advising President Obama" and more, Clinton cast herself as the defender of Obama's legacy and Sanders as someone who'd toss out his accomplishments.

There are three reasons for the strategy: Obama remains popular with Democrats. She has a strong claim to the President's legacy having served in his Cabinet as his top foreign policy officer. And minority voters favor Obama and Clinton over Sanders.

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Clinton is eyeing South Carolina as a firewall -- a place she can regain her footing even if Sanders wins Iowa and New Hampshire, two states that are whiter and more liberal than the Democratic electorate overall.

Her attacks on Sanders were all designed to drive a wedge between him and Obama.

Photos: Hillary Clinton's life in the spotlight Photos: Hillary Clinton's life in the spotlight Hillary Clinton accepts the Democratic Party's nomination for president at the Democratic National Convention in Philadelphia on July 28, 2016. The former first lady, U.S. senator and secretary of state was the first woman to lead the presidential ticket of a major political party. Hide Caption 1 of 43 Photos: Hillary Clinton's life in the spotlight Before marrying Bill Clinton, she was Hillary Rodham. Here she attends Wellesley College in Massachusetts. Her commencement speech at Wellesley's graduation ceremony in 1969 attracted national attention. After graduating, she attended Yale Law School. Hide Caption 2 of 43 Photos: Hillary Clinton's life in the spotlight Rodham was a lawyer on the House Judiciary Committee, whose work led to impeachment charges against President Richard Nixon in 1974. Hide Caption 3 of 43 Photos: Hillary Clinton's life in the spotlight In 1975, Rodham married Bill Clinton, whom she met at Yale Law School. He became the governor of Arkansas in 1978. In 1980, the couple had a daughter, Chelsea. Hide Caption 4 of 43 Photos: Hillary Clinton's life in the spotlight Arkansas' first lady, now using the name Hillary Rodham Clinton, wears her inaugural ball gown in 1985. Hide Caption 5 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons celebrate Bill's inauguration in Little Rock, Arkansas, in 1991. He was governor from 1983 to 1992, when he was elected President. Hide Caption 6 of 43 Photos: Hillary Clinton's life in the spotlight Bill Clinton comforts his wife on the set of "60 Minutes" after a stage light broke loose from the ceiling and knocked her down in January 1992. Hide Caption 7 of 43 Photos: Hillary Clinton's life in the spotlight In June 1992, Clinton uses a sewing machine designed to eliminate back and wrist strain. She had just given a speech at a convention of the International Ladies' Garment Workers Union. Hide Caption 8 of 43 Photos: Hillary Clinton's life in the spotlight During the 1992 presidential campaign, Clinton jokes with her husband's running mate, Al Gore, and Gore's wife, Tipper, aboard a campaign bus. Hide Caption 9 of 43 Photos: Hillary Clinton's life in the spotlight Clinton accompanies her husband as he takes the oath of office in January 1993. Hide Caption 10 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons share a laugh on Capitol Hill in 1993. Hide Caption 11 of 43 Photos: Hillary Clinton's life in the spotlight Clinton unveils the renovated Blue Room of the White House in 1995. Hide Caption 12 of 43 Photos: Hillary Clinton's life in the spotlight Clinton waves to the media in January 1996 as she arrives for an appearance before a grand jury in Washington. The first lady was subpoenaed to testify as a witness in the investigation of the Whitewater land deal in Arkansas. The Clintons' business investment was investigated, but ultimately they were cleared of any wrongdoing. Hide Caption 13 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons hug as Bill is sworn in for a second term as President. Hide Caption 14 of 43 Photos: Hillary Clinton's life in the spotlight The first lady holds up a Grammy Award, which she won for her audiobook "It Takes a Village" in 1997. Hide Caption 15 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons dance on a beach in the U.S. Virgin Islands in January 1998. Later that month, Bill Clinton was accused of having a sexual relationship with former White House intern Monica Lewinsky. Hide Caption 16 of 43 Photos: Hillary Clinton's life in the spotlight Clinton looks on as her husband discusses the Monica Lewinsky scandal in the Roosevelt Room of the White House on January 26, 1998. Clinton declared, "I did not have sexual relations with that woman." In August of that year, Clinton testified before a grand jury and admitted to having "inappropriate intimate contact" with Lewinsky, but he said it did not constitute sexual relations because they had not had intercourse. He was impeached in December on charges of perjury and obstruction of justice. Hide Caption 17 of 43 Photos: Hillary Clinton's life in the spotlight The first family walks with their dog, Buddy, as they leave the White House for a vacation in August 1998. Hide Caption 18 of 43 Photos: Hillary Clinton's life in the spotlight President Clinton makes a statement at the White House in December 1998, thanking members of Congress who voted against his impeachment. The Senate trial ended with an acquittal in February 1999. Hide Caption 19 of 43 Photos: Hillary Clinton's life in the spotlight Clinton announces in February 2000 that she will seek the U.S. Senate seat in New York. She was elected later that year. Hide Caption 20 of 43 Photos: Hillary Clinton's life in the spotlight Clinton makes her first appearance on the Senate Environment and Natural Resources Committee. Hide Caption 21 of 43 Photos: Hillary Clinton's life in the spotlight Sen. Clinton comforts Maren Sarkarat, a woman who lost her husband in the September 11 terrorist attacks, during a ground-zero memorial in October 2001. Hide Caption 22 of 43 Photos: Hillary Clinton's life in the spotlight Clinton holds up her book "Living History" before a signing in Auburn Hills, Michigan, in 2003. Hide Caption 23 of 43 Photos: Hillary Clinton's life in the spotlight Clinton and another presidential hopeful, U.S. Sen. Barack Obama, applaud at the start of a Democratic debate in 2007. Hide Caption 24 of 43 Photos: Hillary Clinton's life in the spotlight Obama and Clinton talk on the plane on their way to a rally in Unity, New Hampshire, in June 2008. She had recently ended her presidential campaign and endorsed Obama. Hide Caption 25 of 43 Photos: Hillary Clinton's life in the spotlight Obama is flanked by Clinton and Vice President-elect Joe Biden at a news conference in Chicago in December 2008. He had designated Clinton to be his secretary of state. Hide Caption 26 of 43 Photos: Hillary Clinton's life in the spotlight Clinton, as secretary of state, greets Russian Prime Minister Vladimir Putin during a meeting just outside Moscow in March 2010. Hide Caption 27 of 43 Photos: Hillary Clinton's life in the spotlight The Clintons pose on the day of Chelsea's wedding to Marc Mezvinsky in July 2010. Hide Caption 28 of 43 Photos: Hillary Clinton's life in the spotlight In this photo provided by the White House, Obama, Clinton, Biden and other members of the national security team receive an update on the mission against Osama bin Laden in May 2011. Hide Caption 29 of 43 Photos: Hillary Clinton's life in the spotlight Clinton checks her Blackberry inside a military plane after leaving Malta in October 2011. In 2015, The New York Times reported that Clinton exclusively used a personal email account during her time as secretary of state. The account, fed through its own server, raises security and preservation concerns. Clinton later said she used a private domain out of "convenience," but admits in retrospect "it would have been better" to use multiple emails. Hide Caption 30 of 43 Photos: Hillary Clinton's life in the spotlight Clinton arrives for a group photo before a forum with the Gulf Cooperation Council in March 2012. The forum was held in Riyadh, Saudi Arabia. Hide Caption 31 of 43 Photos: Hillary Clinton's life in the spotlight Obama and Clinton bow during the transfer-of-remains ceremony marking the return of four Americans, including U.S. Ambassador Christopher Stevens, who were killed in Benghazi, Libya, in September 2012. Hide Caption 32 of 43 Photos: Hillary Clinton's life in the spotlight Clinton ducks after a woman threw a shoe at her while she was delivering remarks at a recycling trade conference in Las Vegas in 2014. Hide Caption 33 of 43 Photos: Hillary Clinton's life in the spotlight Clinton, now running for President again, performs with Jimmy Fallon during a "Tonight Show" skit in September 2015. Hide Caption 34 of 43 Photos: Hillary Clinton's life in the spotlight Clinton testifies about the Benghazi attack during a House committee meeting in October 2015. "I would imagine I have thought more about what happened than all of you put together," she said during the 11-hour hearing. "I have lost more sleep than all of you put together. I have been wracking my brain about what more could have been done or should have been done." Months earlier, Clinton had acknowledged a "systemic breakdown" as cited by an Accountability Review Board, and she said that her department was taking additional steps to increase security at U.S. diplomatic facilities. Hide Caption 35 of 43 Photos: Hillary Clinton's life in the spotlight U.S. Sen. Bernie Sanders shares a lighthearted moment with Clinton during a Democratic presidential debate in October 2015. It came after Sanders gave his take on the Clinton email scandal. "The American people are sick and tired of hearing about the damn emails," Sanders said. "Enough of the emails. Let's talk about the real issues facing the United States of America." Hide Caption 36 of 43 Photos: Hillary Clinton's life in the spotlight Clinton is reflected in a teleprompter during a campaign rally in Alexandria, Virginia, in October 2015. Hide Caption 37 of 43 Photos: Hillary Clinton's life in the spotlight Clinton walks on her stage with her family after winning the New York primary in April. Hide Caption 38 of 43 Photos: Hillary Clinton's life in the spotlight After Clinton became the Democratic Party's presumptive nominee, this photo was posted to her official Twitter account. "To every little girl who dreams big: Yes, you can be anything you want -- even president," Clinton said. "Tonight is for you." Hide Caption 39 of 43 Photos: Hillary Clinton's life in the spotlight Obama hugs Clinton after he gave a speech at the Democratic National Convention in Philadelphia. The president said Clinton was ready to be commander in chief. "For four years, I had a front-row seat to her intelligence, her judgment and her discipline," he said, referring to her stint as his secretary of state. Hide Caption 40 of 43 Photos: Hillary Clinton's life in the spotlight Clinton arrives at a 9/11 commemoration ceremony in New York on September 11. Clinton, who was diagnosed with pneumonia two days before, left early after feeling ill. A video appeared to show her stumble as Secret Service agents helped her into a van. Hide Caption 41 of 43 Photos: Hillary Clinton's life in the spotlight Clinton addresses a campaign rally in Cleveland on November 6, two days before Election Day. She went on to lose Ohio -- and the election -- to her Republican opponent, Donald Trump. Hide Caption 42 of 43 Photos: Hillary Clinton's life in the spotlight After conceding the presidency to Trump in a phone call earlier, Clinton addresses supporters and campaign workers in New York on Wednesday, November 9. Her defeat marked a stunning end to a campaign that appeared poised to make her the first woman elected US president. Hide Caption 43 of 43

She accused Sanders of calling Obama "weak" and "ineffective" when it came to perhaps Clinton's most vulnerable subject, Wall Street reform, and said he'd tried to recruit a primary challenger against Obama in 2011. That year, Sanders had said many Democrats are "deeply disappointed" in Obama's shifts rightward, and a primary opponent could "begin contrasting what is a progressive agenda as opposed to what Obama is doing."

"I am going to defend President Obama for taking on Wall Street, taking on the finance industry and getting results," Clinton said.

Purity vs. pragmatism on health care

Sanders' shoot-for-the-moon liberalism and Clinton's embrace of Obama were clearest in their biggest fight of the evening: health care.

Just two hours before the debate, Sanders had rolled out a tax plan that would fund his Medicare-for-all proposal to scrap private health insurance entirely and replace it with a government-run program.

Sanders offered himself as the true champion of the left's biggest policy dreams.

"What a Medicare-for-all program does is finally provide in this country health care for every man, woman and child as a right," he said. "The truth is that Franklin Delano Roosevelt, Harry Truman ... they believed that health care should be available to all of our people."

Clinton, meanwhile, noted that Democrats had fought for a "public option" in Congress before Obamacare was passed -- but, to liberals' disappointment, hadn't succeeded.

And then she turned to Obama's legacy.

"We have the Affordable Care Act. That is one of the greatest accomplishments of President Obama, the Democratic Party and our country," Clinton said. "To tear it up and start over again, pushing our country back into that kind of a contentious debate, I think is the wrong direction."

Clinton's foreign policy advantage

When the debate shifted to foreign policy in its second hour, Clinton displayed a command that was in sharp contrast to Sanders' quiet.

She gamely handled a question about the moment she handed Russian officials a "reset" button as secretary of state and defended what she got for that symbolic button: a new START Treaty, as well as cooperation on sanctions for Iran.

Sanders, on the other hand, has tried to turn back questions about his foreign policy knowledge by pivoting to judgment. But as the primaries draw near, voters often spend time thinking about the commander-in-chief test -- and Sanders has a long way to go in convincing voters of his readiness to handle foreign affairs.

Nobody's hitting the Republicans

In every Republican debate, all the GOP candidates join together to bash Obama, Clinton and "Obama-Clinton" every chance they can get. And in the earlier Democratic debates, all Clinton and Sanders could talk about was how awful the Republican presidential field -- particularly Trump -- is.

Sunday night, there were very few cross-party attacks.

It's a reflection of a tightening race: Clinton spent her first months of the 2016 campaign refusing to even utter Sanders' name. Now, he's a real threat and her strategy was aimed at him, not the GOP.

Health care and gun control, in particular, have emerged as key splits in the Democratic race where Clinton believes she can win liberal voters from Sanders.

The debate was just a block away from the Emanuel AME Church in Charleston, the site of last year's racially-motivated shooting of nine churchgoers. Clinton used that proximity to criticize Sanders, painting him as cozy with the National Rifle Association.

"He has voted with the NRA, with the gun lobby, numerous times. He voted against the Brady Bill five times. He voted for what we call the Charleston loophole. He voted for immunity for gun makers and sellers," she said.

"He voted to let guns go onto Amtrak, guns go onto national parks. He voted against doing research to figure out how we can save lives."

Sanders didn't interject as the debate shifted topics -- a signal he was ready to move on.

Sanders willing to throw punches

No, he wouldn't swipe at Clinton's husband, saying he wants to focus "on the issues, not Bill Clinton's personal behavior."

But Sanders did show a new willingness to attack Clinton on personal matters. Twice, he hit her for delivering paid speeches to Goldman Sachs -- a move intended to undermine Clinton's credibility on Wall Street reform and call into question her commitment to reforming the political system more broadly.

"I don't get personal speaking fees from Goldman Sachs," he said.

Minutes later, he swung again. "You've received over $600,000 in speaking fees from Goldman Sachs in one year," he said, later turning his focus to criminal justice and noting that "not one of their executives is prosecuted" for actions during the 2008 economic crisis.

The man who often crowed that he'd never run a negative attack ad in his life appears to sense that, with a lead in his sights in Iowa and New Hampshire, it's time to strike.

CORRECTION: An earlier version of this story misidentified the president Bernie Sanders referenced during a defense of his health care plan. It was Harry Truman.