The former New York mayor qualified for Wednesday night's debate on the eve of the critical contest, injecting a combustible new element into an already volatile primary fight.

The other five candidates slated to be on stage with Bloomberg just days before the Nevada caucuses have shown an ability -- and even an eagerness -- to go after the new entrant.

Vermont Sen. Bernie Sanders has argued Bloomberg's money and record won't help motivate the Democratic base. Former South Bend, Indiana, Mayor Pete Buttigieg has labeled Bloomberg a "billionaire who thinks that you can just ... buy your way on to television and win that way." And Massachusetts Sen. Elizabeth Warren , hours after Bloomberg qualified, compared him to President Donald Trump and called him an "egomaniac billionaire."

But Bloomberg is not coming into the debate defenseless.

The former mayor has maintained a focus on Sanders in the day leading up to the debate, hoping that an intense back-and-forth between the two will further cement them as the race's frontrunners. He has questioned Sanders' commitment to a clean campaign, pointing to the hard attacks the senator's supporters online level against his opponents.

For candidates like Buttigieg and Minnesota Sen. Amy Klobuchar , Bloomberg's entry represents the greatest threat to any momentum they still have from Iowa and New Hampshire.

The Democratic debate -- beyond Bloomberg -- is at an inflection point for Biden and Warren, both of whom need to demonstrate the ability to do well after poor performances in New Hampshire.

Here is what to watch for in Wednesday's debate ahead of the Nevada caucuses:

The new target

Bloomberg answers questions from members of the media at the Metropolitan Room on January 3, 2020 in Fayetteville, North Carolina.

Bloomberg's hundreds of millions of dollars in television advertisements have led to this moment: Two-plus hours on stage, unscripted and televised, against opponents who have been rearing to attack him for weeks.

The former New York City mayor's presence on stage is the biggest new factor in Democratic debates for months: Other candidates have exited amid weak polling numbers, but he's entering as a central figure in the Democratic race.

By jumping into the race late, skipping the first four states to vote in the Democratic nominating contest and refusing donations, Bloomberg has avoided debates up until now. But his hundreds of millions of dollars in ad spending has him polling in double digits nationally -- which means, under the Democratic National Committee's recently tweaked qualification thresholds, he's in.

And his rivals are waiting for him.

In CNN town halls Tuesday night in Las Vegas, Sanders, Buttigieg and Klobuchar all said Bloomberg was attempting to buy the election.

Sanders previewed an attack on Bloomberg over stop-and-frisk policing. And Klobuchar said she's glad to get a shot at debating the former New York City mayor.

"I actually thought he should be on the debate stage because I don't think you should just be able to buy your way to the presidency," she said.

Bloomberg's first debate appearance comes amid a barrage of damaging headlines, largely focused on his previous comments about and support for policies widely seen as discriminatory -- including stop-and-frisk policing and redlining . He will also likely face questions over allegations that he made crude remarks and fostered a culture of discrimination against women at Bloomberg L.P. during the late 1980s and 1990s.

Bloomberg, meanwhile, has signaled an eagerness to take on Sanders, with his campaign increasingly criticizing the tactics of the Vermont senator's sometimes rabid online following.

Can Sanders give as good as he gets?

Sanders speaks during the Clark County Democrats Kick Off to Caucus Gala at Tropicana Las Vegas February 15, 2020 in Las Vegas, Nevada.

Previous frontrunners have had a torrid time on debate nights, getting hit from all angles, with their rivals often unfurling new or unexpected lines of attack.

Sanders should expect no less on Wednesday, when the moderate contenders are expected to pick relentlessly at "Medicare for All" in a bid to get in good with Nevada's powerful Culinary Union, which opposes the plan. Bloomberg looks likely to jump on that dogpile, but an even better bet to escalate accusations that Sanders' surrogates are playing dirty -- and that the Vermont senator either hasn't done enough to stop them or is in some way tacitly encouraging it.

Sanders has, in public, repeatedly said that "there is no room in the political revolution for abuse and harassment online," but that is unlikely to quiet the issue. And at a CNN town hall Tuesday night, Sanders put a finer point on it : "I do not believe in online bullying. End of discussion"

The question for Sanders, then, is whether he can deliver the message he wants and not get bogged down by the incoming fire. Sanders is a mostly disciplined debater, hard to knock off script, but he will be under the microscope here and even the smallest blunder -- or misfired attack -- could open up a whopping can of new backlash.

Still, Bloomberg's presence could break to Sanders' benefit.

The heavy-spending billionaire is new to the primary debate stage and represents a new foil for the populists, and perhaps some of the moderates who see him encroaching on their support, to feast on.

Buttigieg, Klobuchar have been preparing for this fight for months

Klobuchar and Buttigieg participate in the Democratic presidential primary debate at Drake University on January 14, 2020 in Des Moines, Iowa.

There isn't much love lost between Buttigieg and Klobuchar.

The two moderates have repeatedly used the debate stage to air their grievances with each other, with the Minnesota senator targeting the former South Bend, Indiana, mayor for his youth and experience on the local level as a way to blunt his rise.

Klobuchar, unlike other candidates, has perplexed Buttigieg on the debate stage. Where he has effectively counter punted against attacks from Warren, Biden and Sanders, Buttigieg hasn't been able to hit Klobuchar with the same fire -- and the Minnesota senator is now surging after a strong debate performance and third place finish in New Hampshire.

That's why Klobuchar bungling an interview in Nevada and awkwardly being unable to name the President of Mexico could provide a flash point in Wednesday's contest.

Buttigieg, who was able to name Mexican President Andrés Manuel López Obrador, hit Klobuchar for her inability to answer the question on Sunday, telling a crowd of supporters in Las Vegas that the misstep shows "that there is more to being prepared than how many years you spent in Washington."

Klobuchar, for her part, has looked to cast Buttigieg as a "newcomer" with no political record.

This fight will have a new resonance on Wednesday given the role Bloomberg is expected to play in the debate. The former New York Mayor, by offering a similar set of moderate policy prescriptions as Buttigieg and Klobuchar, is looking to court some of the same voters and conversations with supporters of each campaign here in Nevada highlight how Bloomberg has made inroads with moderate Democrats.

And Bloomberg has a $60 billion personal fortune to use to get that message out, something neither Buttigieg nor Klobuchar can come close to touching.

Biden eager to attack Bloomberg, too

Biden poses for selfie with a guest prior to the Clark County Democrats Kick Off to Caucus Gala at Tropicana Las Vegas February 15, 2020 in Las Vegas, Nevada.

This is the turning point Biden has been promising.

Written off by many (including Bloomberg, whose campaign is arguing it's a two-man race between the former mayor and Sanders) after a fourth-place finish in Iowa and a fifth-place showing in New Hampshire, Biden is on more comfortable territory in a state with a much larger share of non-white voters.

But the former vice president appears to have lost some benefit of the doubt: The powerful Culinary Union praised him, but didn't endorse him. Former Sen. Harry Reid said he thinks Biden could win, but didn't caucus for him. His fundraising, which has already lagged some of his rivals, faces the threat of donors frozen by Bloomberg's billions or eyeing moderate alternatives like Buttigieg or Klobuchar — right at the moment Biden needs to drastically scale up for Super Tuesday, when 14 states vote on March 3.

Now, he'll try to build momentum on the debate stage -- where he looked feistier than he had before a week ago in New Hampshire.

The question is, which of the many threats he faces will Biden target? Will it be Sanders, whose support among Latinos has become a major asset? Or Buttigieg or Klobuchar, who are part of a crowded centrist lane?

In recent days, Biden has hinted he's most eager to take on Bloomberg -- who is using former President Barack Obama's voice and praise in a national advertising campaign against Obama's former vice president.

In an interview on MSNBC this week, he lambasted Bloomberg over stop-and-frisk policing policies, his failure to endorse then-Sen. Obama in 2008 and his position on Obamacare.

"This is a guy that talked about Obamacare being a disaster and about how he wouldn't support our administration in 2008, so there's a lot to discuss with Michael," Biden said.

Warren is ready to make waves

Warren aknowledges supporters at a primary election night rally, Tuesday, Feb. 11, 2020, in Manchester, N.H.

Warren's staunchest supporters are upset. After a pair of disappointing performances in Iowa and New Hampshire, they feel like the Massachusetts senator has been written off and out of the narrative around a primary still in its earliest stages.

But Warren has an opportunity, perhaps a final one, on Wednesday night to change the conversation. And if there's any doubt it's still possible at this stage, she only needs to look over at Klobuchar, who used her performance at the Granite State debate as a launching pad for a surprisingly strong finish there a few days later.

Warren has cast herself repeatedly as a unity candidate, which will make it a tougher task, but she has shown a willingness in recent days to hit out hard at some of her rivals.

On Tuesday, she offered a preview of what might be coming.

"Mike Bloomberg approved and oversaw a program that surveilled and tracked Muslim communities in mosques, restaurants, and even college campuses --leaving permanent damage. He refuses to apologize for it," she tweeted.

Warren also had some harsh words for Sanders the night before, saying he "has a lot of questions to answer" about the behavior of his supporters online.

"I am particularly worried about what happened in the attacks on members of the Culinary Union, particularly on the women in leadership," Warren told NBC News. "That is not how we build an inclusive Democratic Party. And it is not how we (beat) Donald Trump. We do not build on a foundation of hate."