(CNN) Donald Trump will live to fight another day -- but it took the nastiest, most bitterly personal presidential debate in recent memory for the Republican nominee to stanch the downward plunge.

Trump's campaign was in free fall when he entered the debate hall Sunday night, reeling from the revelation of a 2005 video in which he spoke of women in lewd and sexually aggressive terms. The video sparked a dramatic rebuke of Trump, with dozens of Republicans in Washington and around the country saying the billionaire should step aside and let his running mate, Indiana Gov. Mike Pence, lead the GOP ticket.

The icy tone was set early when decades of tradition eroded as Trump and Clinton declined to shake each other's hand.

Trump fought back in the only way he knew how -- throwing out a battery of vicious counter punches. He vowed to prosecute Clinton if he is elected, and then throw her in jail. With her husband and daughter in the audience, Trump branded Bill Clinton a serial abuser of women hours after appearing alongside several women who allege the former president assaulted them.

Trump seemingly dismissed the significance of the vulgar language he was caught on tape using toward women a decade ago, apologizing for his conduct but repeatedly saying his remarks were just "locker room talk" that did not reflect his real character.

Photos: The second presidential debate Republican nominee Donald Trump faces off with Democratic nominee Hillary Clinton during the second presidential debate, which took place Sunday, October 9, at Washington University in St. Louis. Hide Caption 1 of 25 Photos: The second presidential debate The two candidates shake hands at the end of the debate. They did not shake at the beginning. Hide Caption 2 of 25 Photos: The second presidential debate Clinton responds to a question during the event, which used a town-hall format that included questions from undecided voters. Hide Caption 3 of 25 Photos: The second presidential debate Trump greets Clinton before the start of the debate. Hide Caption 4 of 25 Photos: The second presidential debate The event in St. Louis was the second of three scheduled debates. Election Day is less than a month away. Hide Caption 5 of 25 Photos: The second presidential debate Trump looks on as Clinton answers a question. Hide Caption 6 of 25 Photos: The second presidential debate Clinton delivers an answer. Hide Caption 7 of 25 Photos: The second presidential debate Members of the audience listen to the debate. The 40 town-hall participants, selected by Gallup, were described as "uncommitted voters." Hide Caption 8 of 25 Photos: The second presidential debate Trump leans against a chair during the debate. Hide Caption 9 of 25 Photos: The second presidential debate A stage shot from the candidates' point of view. Hide Caption 10 of 25 Photos: The second presidential debate Trump addresses remarks toward Clinton. Hide Caption 11 of 25 Photos: The second presidential debate Trump goes on the offensive. Hide Caption 12 of 25 Photos: The second presidential debate The debate was moderated by CNN's Anderson Cooper and ABC's Martha Raddatz. Hide Caption 13 of 25 Photos: The second presidential debate Trump answers a question during the debate. Hide Caption 14 of 25 Photos: The second presidential debate Clinton looks on as Trump speaks. Hide Caption 15 of 25 Photos: The second presidential debate Trump responds to a question during the debate. Hide Caption 16 of 25 Photos: The second presidential debate Clinton speaks during the debate. Hide Caption 17 of 25 Photos: The second presidential debate At the beginning of the debate, Trump apologized for lewd remarks he made during a 2005 video that surfaced last week. He called it "locker room talk" before pivoting to terrorism and "bad things happening" in the world. Hide Caption 18 of 25 Photos: The second presidential debate The two candidates walk to their positions at the start of the debate. Hide Caption 19 of 25 Photos: The second presidential debate Both candidates kept their distance at the start of the debate. Hide Caption 20 of 25 Photos: The second presidential debate Photographers work behind members of Trump's family: from left, Trump's wife, Melania, and his children Ivanka, Eric and Donald Jr. Hide Caption 21 of 25 Photos: The second presidential debate Clinton's husband, former U.S. President Bill Clinton, shakes hands with Ivanka Trump before the debate. Hide Caption 22 of 25 Photos: The second presidential debate Melania Trump passes Bill Clinton after their handshake. Hide Caption 23 of 25 Photos: The second presidential debate Bill Clinton, right, sits with his daughter, Chelsea, and Chelsea's husband, Marc Mezvinsky. Hide Caption 24 of 25 Photos: The second presidential debate Also sitting in the audience were, from left, Kathleen Willey, Juanita Broaddrick and Kathy Shelton. Less than two hours before the debate, those three -- along with Paula Jones -- appeared in a Trump news conference to speak out against the Clintons. Willey, Broaddrick and Jones have previously accused former President Bill Clinton of inappropriate sexual behavior. Shelton's rapist was defended by Hillary Clinton as a young lawyer. That man was convicted of a lesser charge and served 10 months in jail. Hide Caption 25 of 25

Clinton, however, said that incident did provide a true picture of Trump's character. She spoke of her years fighting Republicans on policy but said she never questioned their fitness to serve as president until now.

"Donald Trump is different," Clinton warned.

In the process, it seemed as if American politics changed in the course of one nasty night. The once sacred tradition of a presidential debate -- where candidates typically trade barbs over their vision of the country's future instead of personal humiliations -- exploded into something quite chilling.

Trump glowered, interrupted, and prowled the stage at Washington University in St. Louis, calling Clinton a "devil" and "liar" with "hate in her heart." The performance likely electrified his fiercely loyal supporters but may have done little to widen his appeal among more moderate swing state voters.

A CNN/ORC poll found 57% of debate watchers thought Clinton won compared to 34% who thought Trump came out on top. The poll only represents the views of people who watched the debate and has a slight Democratic advantage compared to CNN polls of all Americans.

Clinton didn't take Trump's bait, staying calm when he declared "Bill Clinton was abusive to women. Hillary Clinton attacks those same women." She didn't take the bait, repeating first lady Michelle Obama's philosophy articulated at the Democratic convention: "When they go low, we go high."

Pacing the stage

Trump paced the stage for much of the debate, which was moderated by CNN's Anderson Cooper and ABC's Martha Raddatz. He frequently interrupted Clinton and had trouble standing still while she spoke, sometimes appearing in her camera shot. He lost his composure at one point after a fierce exchange with Clinton about her emails, accusing the moderators of not addressing the issue even though Raddatz had asked a question about it.

"Nice, one on three" Trump said, claiming that the moderators were biased against him.

Hours earlier, Trump made a surprise appearance with women who have in the past accused Bill Clinton of inappropriate sexual advances. The women later attended the debate as members of the audience.

During the debate, Trump came across as more serious, prepared and less prone to losing his cool than in the first presidential debate two weeks ago when he was seen as the clear loser.

Clinton was less dominant than in the first debate and sometimes less effective in parrying Trump's attacks in an encounter far more frosty and bitter than in their first clash. But no other presidential candidate in history has faced the personal buzzsaw that Trump represented on Sunday night.

And Trump did not just aim his fire at the Clintons.

He took a swipe at Pence, who declined to go out in public and defend his running mate after the emergence of the video on Friday.

Trump slapped down Pence's statement during last week's vice presidential debate, when the Indiana governor said the US should be prepared militarily to target Syrian government assets to help alleviate the siege of the key city of Aleppo.

"He and I haven't spoken, and I disagree," Trump said.

After the debate finished, Pence tweeted he was "proud to stand" with Trump and congratulated him on a "big debate win." And Kellyanne Conway told CNN's Dana Bash that Pence and Trump spoke after the debate.

Syria was one of the few foreign policy items tackled during the debate. While Trump was far more polished in attacking Clinton's liabilities such as her email server and the weakest aspects of her record as secretary of state. But he often struggled when the debate turned to in-depth policy questions.

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

He suggested he would align himself with some of America's most hostile enemies, including Russia and the government of Syrian President Bashar al-Assad, to fight ISIS.

"I don't like Assad at all, but Assad is killing ISIS," Trump said. "Russia is killing ISIS. And Iran is killing ISIS. And those three have now lined up because of our weak foreign policy."

Obama administration officials have repeatedly said Russia and Syria are not focusing on ISIS but are instead targeting the moderate opposition, some of which are backed by the US, and defenseless Syrian civilians.

Clinton, meanwhile, branded her rival as outside the American mainstream and unfit to be president.

"He never apologizes for anything to anyone," Clinton said, hammering Trump for his treatment of the parents of a Muslim solider killed in Iraq, his disparagement of a judge with Mexican heritage, for his mocking of a disabled New York Times reporter and his birtherism crusade against President Barack Obama.

Perhaps the most stunning moment of the debate occurred when Trump threatened to use the power of the American government to investigate Clinton over the private email server she used as secretary of state.

Photos: The week in politics Republican presidential candidate Donald Trump appears in a video posted to his Twitter account early Saturday, October 8, apologizing for vulgar and sexually aggressive remarks he made a decade ago regarding women. "I said it, I was wrong and I apologize," Trump said of footage from a previously unaired taping of "Access Hollywood" that surfaced Friday. The aftermath of the leaked footage has seen multiple top Republican leaders rescinding their endorsements of Trump. Hide Caption 1 of 18 Photos: The week in politics Democratic presidential candidate Hillary Clinton hugs Zianna Oliphant on stage after speaking at a church in Charlotte, North Carolina, on Sunday, October 2. Zianna, 9, garnered national attention when she tearfully spoke at a Charlotte City Council meeting about recent police killings of African-Americans. Clinton told the congregation she "wouldn't be able to stand it" if her own grandchildren ever felt the kind of fear and worry that Oliphant and others have expressed. Hide Caption 2 of 18 Photos: The week in politics Demonstrators hold signs in Washington on Tuesday, October 4, urging the US Senate to hold a confirmation vote for Supreme Court nominee Merrick Garland. President Barack Obama nominated Garland to fill the vacancy left by Antonin Scalia, who died in February. Hide Caption 3 of 18 Photos: The week in politics Kenan Thompson plays "Family Feud" host Steve Harvey in a politically themed "Saturday Night Live" sketch on Saturday, October 1. Playing on the fictitious Team Trump, from left: Kate McKinnon as Donald Trump campaign manager Kellyanne Conway, Margot Robbie as Ivanka Trump, Alex Moffat as Eric Trump, Mikey Day as Donald Trump Jr. and Bobby Moynihan as New Jersey Gov. Chris Christie. Hide Caption 4 of 18 Photos: The week in politics US Sen. Tim Kaine, left, and Indiana Gov. Mike Pence take part in the vice presidential debate on Tuesday, October 4. Kaine is the running mate to Democratic nominee Hillary Clinton. Pence is on the ticket with Republican nominee Donald Trump. Hide Caption 5 of 18 Photos: The week in politics Vice President Joe Biden points at an 8-month-old boy during a Hillary Clinton rally in Orlando on Monday, October 3. Hide Caption 6 of 18 Photos: The week in politics US Secretary of State John Kerry delivers a speech at the German Marshall Fund in Brussels, Belgium, on Tuesday, October 4. Hide Caption 7 of 18 Photos: The week in politics Peter Riehl, of Lone Tree, Colorado, holds up the hand of Republican presidential candidate Donald Trump during a campaign rally in Loveland, Colorado, on Monday, October 3. Hide Caption 8 of 18 Photos: The week in politics President Barack Obama helps Pittsburgh Penguins captain Sidney Crosby move the Stanley Cup during the hockey team's visit to the White House on Thursday, October 6. Hide Caption 9 of 18 Photos: The week in politics During a ceremony at the Pentagon on Monday, October 3, US Defense Secretary Ash Carter stands with members of the military who competed at the 2016 Olympics in Rio de Janeiro. Hide Caption 10 of 18 Photos: The week in politics Matthew Cohen is dressed up like Republican presidential candidate Donald Trump at a Trump rally in Henderson, Nevada, on Wednesday, October 5. Hide Caption 11 of 18 Photos: The week in politics People attend the South by South Lawn event at the White House on Monday, October 3. Hide Caption 12 of 18 Photos: The week in politics Democratic presidential nominee Hillary Clinton arrives at an airport in Middletown, Pennsylvania, on Tuesday, October 4. Hide Caption 13 of 18 Photos: The week in politics President Barack Obama makes a statement after being briefed on Hurricane Matthew on Wednesday, October 5. "I want to emphasize to the public, this is a serious storm," Obama said, urging people to follow local evacuation orders. Hide Caption 14 of 18 Photos: The week in politics People in Akron, Ohio, wait for a speech by Democratic presidential candidate Hillary Clinton on Monday, October 3. Hide Caption 15 of 18 Photos: The week in politics Former US President Jimmy Carter sits in the stands for an Atlanta Braves baseball game on Sunday, October 2. Hide Caption 16 of 18 Photos: The week in politics California Rep. Loretta Sanchez does a "dab" at the end of her debate with state Attorney General Kamala Harris on Wednesday, October 5. The two Democrats are running for US Senate. Hide Caption 17 of 18 Photos: The week in politics Students stand in on the stage as preparations are made for the second presidential debate between Republican presidential nominee Donald Trump and Democratic presidential nominee Hillary Clinton at Washington University in St. Louis on Saturday, October 8. The debate is set to air Sunday, October 9. Hide Caption 18 of 18

"If I win, I am going to instruct my attorney general to get a special prosecutor to look into your situation. There has never been so many lies, so much deception. There has never been anything like it," Trump said.

Clinton replied: "it's just awfully good that someone with the temperament of Donald Trump is not in charge of the law in our country."

Trump hit back: "Because you'd be in jail."

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The exchange was remarkable, even in an election campaign that has repeatedly redefined the scope of acceptable political discourse. Eric Holder, President Barack Obama's former attorney general, responded on Twitter: "So @realDonaldTrump will ORDER his AG to take certain actions. When Nixon tried that his AG courageously resigned. Trump is dangerous/unfit."

Asked by one of the undecided voters in the town hall style debate audience to find something she admired about Trump, Clinton mentioned his family, who she said had inherited their father's drive.

"His children are incredibly able and devoted, and I think that says a lot about Donald," Clinton said of his family, who attended the debate as did her husband, daughter and son-in-law.

Trump admitted to some grudging respect for Clinton's resilience.

"I will say this about Hillary: She doesn't quit. She doesn't give up. I respect that. I tell it like it is. She's a fighter," Trump said.

The night ended with a tepid handshake that was missing at the outset before the rivals retreated to the embrace of their families to lick their wounds.