Elizabeth Warren and each of the four other remaining Democratic presidential contenders wasted no time in scorching Michael Bloomberg in Wednesday night's off-the-rails debate in Las Vegas, as the former New York City mayor sought to fend off accusations that he's essentially buying his way into the race with his vast fortune.

In her first turn at the microphone, Warren asserted that she would support whoever wins the nomination, but warned that Democrats "take a huge risk if we just substitute one arrogant billionaire for another."

She said the field is running against somebody "who calls women fat broads and horse-faced lesbians -- and no, I’m not talking about Donald Trump, I’m talking about Mayor Bloomberg."

As some attendees cheered, she added, "We are not going to win if we have a nominee who has a history of hiding his tax returns, of harassing women, and of supporting racist policies like redlining and stop-and-frisk."

Bernie Sanders, meanwhile, warned that Bloomberg couldn't be elected because he wouldn't be able to assemble a diverse coalition of voters.

"Mr. Bloomberg had policies in New York City of stop-and-frisk that went after African American and Latino people in an outrageous way," Sanders said.

"I don't think there's any chance of the senator beating President Trump," Bloomberg responded flatly, asserting that Americans don't want to lose their private health care plans under his "Medicare for All" initiative.

That was a point that Pete Buttigieg argued later, as the debate quickly descended into a crossfire among the candidates: "We can actually deliver health care without taking it away from anyone," he said, during a discussion with Sanders.

Buttigieg added that Sanders' plans would cost "$50 trillion; he's only explained $25 trillion in revenue, which means the hole in there is bigger than the entire economy of the United States." Sanders responded that Medicare for All would save $450 billion a year by reducing administrative costs -- a claim that numerous studies have disputed.

Buttigieg also reminded the audience that Bloomberg hasn't always been a Democrat, saying the party should nominate someone who at least "actually" belongs to the party. Bloomberg, for his part, epeatedly touted his experience as an executive and his ability to take on Trump, boasting: “I’m a New Yorker. I know how to take on an arrogant con man.”

Later, Joe Biden hammered Bloomberg on his stop-and-frisk policy, saying it "violated every right people have."

Warren picked up that point, accusing Bloomberg of "willful ignorance" and "shutting out" the sounds of protests on his own streets. "You need a different apology here, Mr. Mayor," Warren said, after Bloomberg said he regretted the implementation of stop-and-frisk.

Separately, Warren unexpectedly took aim at Amy Klobuchar, who bested Warren in the New Hampshire primary. Her health care plan, Warren mocked, was "like a Post-It note: 'Insert plan here.'" The broadside prompted a stunned reaction in the debate hall.

"I must say I take personal offense, since Post-It notes were invented in my state," Klobuchar said in response, to laughter. She emphasized that her plan was to establish a public option. "You don't put your money on a number that's not even on the wheel," Klobuchar added, noting that "two-thirds of the Democratic senators are not on that bill," and many House members see the problems in "blowing up the Affordable Care Act."

"We need to improve the Affordable Care Act, not blow it up," Klobuchar said.

Biden interjected that he was the only person on the stage who had "gotten anything done" on health care, referring to the ACA.

Bloomberg was on the debate stage for the first time, after the Democratic National Committee (DNC) abruptly dropped the requirement that candidates meet an individual donor threshold to qualify. Bloomberg donated $300,000 to the DNC shortly before joining the presidential race last year.

“To now change the rules in the middle of the game to accommodate Mike Bloomberg, who is trying to buy his way into the Democratic nomination, is wrong,” Bernie Sanders adviser Jeff Weaver said after the debate rules were revealed. “That’s the definition of a rigged system.”

Bloomberg faced fierce attacks from Biden and Sanders hours before the debate began, raising the likelihood of a raucous affair just three days before Nevada voters decide the third contest of the Democratic Party's turbulent 2020 primary season. As Biden’s poll numbers have slid following his fourth- and fifth-place finishes in Iowa and New Hampshire, Bloomberg’s seen his poll numbers soar, thanks in part to roughly $400 million he’s spent to run ads across the country on TV, Facebook and Google.

Bloomberg won't be on the ballot Saturday, yet he was expecting to face intense scrutiny on national television for the first time, having faced relatively little in his surprisingly swift rise from nonpartisan megadonor to top-tier contender.

“He is going to have a giant target on his back from all sides,” said Democratic strategist Brian Brokaw. “It’ll either all come together brilliantly or could fall apart very quickly.”

On CNN early in the day, Sanders' national press secretary Briahna Joy Gray tried to rebut questions surrounding the Vermont senator’s health by pointing to Bloomberg, who she said had also “suffered heart attacks in the past.”

Sanders suffered a heart attack last fall and released letters from doctors attesting to his health. But Bloomberg has never suffered a heart attack; he released a doctors’ letter last year that said he did undergo coronary stent surgery in 2000.

Gray later walked back her statement, saying on Twitter that she “misspoke” about Bloomberg’s health.

Separately, the Biden campaign took on Bloomberg over ads that feature him working closely with former President Barack Obama. The Biden campaign posted a video on social media highlighting past comments Bloomberg made criticizing Obama on health care and climate change and accusing him of failing to address racism during his term.

The video also includes a clip of Bloomberg declaring “I’m a friend of Donald Trump’s, he’s a New York icon.” Read more at FOX News