CHARLESTON, S.C. (AP) — Democrats unleashed a roaring assault against Bernie Sanders and seized on Mike Bloomberg's past with women in the workplace during a contentious debate that tested the strength of the two men at the center of the party's presidential nomination fight.

As the undeniable Democratic front-runner, Sanders faced the brunt of the attacks for much of the night, and for one of the few times, fellow progressive Elizabeth Warren was among the critics. The Massachusetts senator pressed the case that she could execute ideas that the Vermont senator could only talk about.

"Bernie and I agree on a lot of things," she said. "But I think I would make a better president than Bernie."

A group of moderates, meanwhile, fought to emerge as the chief Sanders alternative.

Former Vice President Joe Biden, who is seeking a strong win in South Carolina to keep his campaign afloat, argued only he has the experience to lead in the world. Minnesota Sen. Amy Klobuchar repeatedly contended that she alone could win the votes of battleground state moderates. And former South Bend, Indiana, Mayor Pete Buttigieg pointed to Sanders' self-described democratic socialism and his recent comments expressing admiration for Cuban dictator Fidel Castro's push for education.

"I am not looking forward to a scenario where it comes down to Donald Trump with his nostalgia for the social order of the 1950s and Bernie Sanders with a nostalgia for the revolutionary politics of the 1960s," Buttigieg declared.

But the moderates did little to draw separation among themselves, a dynamic that has so far only benefited the Vermont senator. Sanders fought back throughout the night, pointing to polls that showed him beating the Republican president and noting all the recent attention he's gotten: "I'm hearing my name mentioned a little bit tonight. I wonder why."

Trump, who returned to Washington early Wednesday after a two-day trip to India, responded to a reporter's shouted question about whether he'd seen the debate: "I did," he said while stepping into a car. "Not too good, not too good."

The intensity of Tuesday's forum, with candidates repeatedly shouting over each other, reflected the reality that the Democrats' establishment wing is quickly running out of time to stop Sanders' rise. Even some critics, Bloomberg among them, conceded that Sanders could build an insurmountable delegate lead as soon as next week.

The 10th debate of the 2020 primary season, sponsored by CBS and the Congressional Black Caucus Institute, was just four days before South Carolina's first-in-the-South primary and one week before more than a dozen states vote on Super Tuesday. The Democratic White House hopefuls will not stand side by side on the debate stage again until the middle of March. That made Tuesday's debate likely the last chance for some candidates to save themselves and alter the trajectory of the nomination fight.

Though Sanders was at the center of the attacks, the night was actually something of a high point in his political career. After spending nearly three decades as an agitator who delighted in tearing into his party's establishment, that very party establishment was suddenly fighting to take him down, a clear sign of his rising status as the leading candidate for the nomination.

Bloomberg also faced sustained attacks that gave him an opportunity to redeem himself after a bad debate debut one week earlier. Warren cut hard at his record as a businessman, bringing up reports of one particular allegation that he told a pregnant employee "to kill it," a reference to the woman's unborn child. Bloomberg fiercely denied the allegation, but acknowledged he sometimes made comments that were inappropriate.

Bloomberg "cannot earn the trust of the core of the Democratic Party," Warren said. "He is the riskiest candidate standing on this stage."

But Bloomberg will likely remain a force in the contest even as other candidates may quickly face tough choices about the sustainability of their campaigns. Bloomberg has already spent more than $500 million on a national advertising campaign, and his fortune ensures he will remain a factor at least through Super Tuesday.

From the earliest moments of the debate, Bloomberg sought to portray a clear contrast with Sanders. He said Trump and Russian President Vladimir Putin agree that Sanders would be the best outcome for the Democrats.

"Vladimir Putin thinks Donald Trump should be president of the United States and that's why Russia is helping you get elected so you lose to him," the former New York mayor said.

Last week, Sanders acknowledged that he'd be been briefed by intelligence officials who said that Russia is attempting to interfere in the elections to benefit him. He responded to Bloomberg on Tuesday with a direct statement for Putin: "Hey, Mr. Putin, if I'm president of the United States, trust me you're not going to interfere in any more American elections.'"

But the skepticism for Sanders was a constant.

Buttigieg raised concerns that a Sanders nomination would cost Democrats the House and make it harder to retake the Senate.

"We're not going to win these critical, critical House and Senate races if people in those races have to explain why the nominee of the Democratic Party is telling people to look at the bright side of the Castro regime," Buttigieg said.

And Bloomberg said Sanders wouldn't be able to build a winning coalition that includes Republicans unhappy with Trump's performance in the White House.

"Can anyone in this room imagine moderate Republican going over and voting for him," he said. "You have to do that or you can't win."

Warren, who raised questions about Sanders' electability earlier in the night, intercepted that criticism, arguing that a "progressive agenda is popular."

The South Carolina contest offers the first real look at the influence African American voters play in the Democrats' presidential nomination process. Biden is trying to make a big impression in in the state, where he was long viewed as the unquestioned front-runner because of his support from black voters. But heading into Saturday's primary after three consecutive underwhelming finishes, there were signs that the former vice president's African American support may be slipping.

One reason: Tom Steyer. The billionaire activist has been pouring money into African American outreach, which threatens to peel away some of the support Biden badly needs.

Steyer noted Tuesday that he was the only candidate on stage who supported reparations for descendants of slaves.

Bloomberg, who for years defended New York's stop-and-frisk policing policy that a federal court struck down, made an overt appeal to the nation's black voters.

"I know that if I were black, my success would have been a lot harder to achieve," he said. "That's a fact that we've got to do something about."

The attacks against Sanders did not slow as the night went on.

He was forced to defend his position on Israel, having condemned the American ally for its treatment of Palestinians.

"Sadly, tragically in Israel, through Bibi Netanyahu, you have a reactionary racist, who is now running that country," said Sanders. who would be the country's first Jewish president. He added: "What you cannot ignore is the suffering of the Palestinian people."

And Biden slammed Sanders for his record on gun control, seizing on the Vermont senator's support of the 2005 Protection of Lawful Commerce in Arms Act, legislation that protects gun manufacturers and sellers from laws that attempt to hold them liable for dealing firearms that end up in the hand of criminals.

"My friend to my right, and others, have in fact also given in to gun manufacturers absolute immunity," said Biden. "Imagine if I stood here and said, 'We give immunity to drug companies. We give immunity to tobacco companies.'

"That has caused carnage on our streets. "

Sanders proudly highlighted his "D minus" rating from the pro-gun organization. And just last week, several gun control advocates who survived the Parkland, Florida, school shooting endorsed him.

Moving forward from the fiery debate, there are questions about the Democratic Party's ability to unify behind a nominee .

Klobuchar perhaps summed up her party's challenge best: "If we spend the next 10 months tearing our party apart, Donald Trump is going to spend the next four years tearing this country apart."

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Peoples and Madhani reported from Washington.

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