LAS VEGAS — Mike Bloomberg is in.

In a development that promises to shake up the race, the wealthy entrepreneur and former mayor of New York City qualified for Wednesday’s Democratic presidential debate with just hours to spare after a new poll showed him surging nationally into the runner-up position behind Sen. Bernie Sanders, I-Vt.

The two campaigns are spoiling for a fight and increasingly depicting the contest as a two-man race. Each views the other as an ideal foil — a self-described democratic socialist calling for a “revolution” to take on the wealthy elite, and an economically centrist billionaire who preaches the virtues of capitalism and hard work.

A weekend spat between Sanders and Bloomberg appears likely to spill over into the six-person debate that will also include Pete Buttigieg, Elizabeth Warren, Joe Biden and Amy Klobuchar. The debate will be hosted by NBC News, MSNBC and the Nevada Independent, beginning at 9 p.m. ET/ 6 p.m. PT.

Here are five things to watch for on Wednesday:

The Bloomberg factor

The debate will test Bloomberg’s ability to handle the scrutiny he has largely escaped until recently. It’ll be the first time he’ll share the stage with his Democratic rivals and be judged by voters in the sort of uncontrolled environment that even his money cannot buy.

A warm welcome appeared unlikely. “It’s a shame Mike Bloomberg can buy his way into the debate,” Warren tweeted Tuesday. “But at least now primary voters curious about how each candidate will take on Donald Trump can get a live demonstration of how we each take on an egomaniac billionaire.”

Bloomberg has used his personal fortune to blitz the airwaves with a TV ad campaign unprecedented in scope and to build an organization that is the envy of rivals. He’s skipping the early contests and instead barnstorming Super Tuesday states with his eyes on bigger delegate prizes. He has shot up in polls and been asked to answer for elements of his record that could alienate Democratic voters, whether it’s issues like “stop and frisk” or Obamacare to accusations from women of making vulgar and sexist remarks.

Central to Bloomberg’s appeal among Democrats is the belief that he’s rich enough and tough enough to go toe-to-toe with Trump. It’s one thing to cut ads and publish tweets denigrating the president. Can Mayor Mike demonstrate that intensity in a debate?

A new front-runner in Sanders

As Biden slips off his front-runner perch, Sanders has assumed the top step of the podium in multiple recent surveys after his popular vote win in Iowa and victory in New Hampshire. He also enters the Nevada caucuses in pole position, according to a recent poll by The Las Vegas Review-Journal.

Sanders, remarkably, has faced modest or sparing criticism from major rivals in recent debates. That may change in Las Vegas as Democrats confront a reality that many of them never expected to materialize: The Vermont senator is currently the odds-on favorite to win the nomination.

Sanders’ consolidation of liberal voters has been most problematic for Warren, relegating her to disappointing third- and fourth-place finishes in the first two states. Warren has been reluctant to criticize him as she pitches herself as a figure who can end the intra-party squabbles and marshal a unified Democratic base behind her candidacy in the fall. Biden has criticized Sanders in prior debates, and may feel pressure to up his game.

In recent days, Biden, Bloomberg and Warren have all criticized Sanders for the unruly behavior of some of his online supporters after leaders of the Culinary Workers Union in Nevada — who oppose Sanders’ health care plan — received threatening messages. While Sanders has called such behavior “unacceptable” and urged respect, it hasn’t placated his rivals — and they’ll have an opportunity to tell him that face to face.

Pete and Amy: Can they widen their bases?

Nevada marks a new phase of the Democratic primary that will knock out candidates who fail to attract black and Latino voters. How will Buttigieg and Klobuchar try to address that problem in the debate? Keep an eye on what issues they emphasize and whether they adjust their rhetoric.

Buttigieg has wowed voters with his intellect and tranquil demeanor, capping off an impressive rise from a midsize-city mayor to top-tier presidential contender with a delegate victory in Iowa and a silver medal in New Hampshire. Klobuchar, who had been languishing in the polls, rode a last-minute wave of “Klomentum” to a third-place finish in New Hampshire that breathed new life into her campaign.

Now comes the hard part for the two middle-of-the-road Midwesterners. Both have a base that is overwhelmingly white — not such a problem in Iowa and New Hampshire, but it’s unsustainable in Nevada, South Carolina and Super Tuesday.

Can Biden and Warren recover?

Time is running out for one-time front-runners Biden and Warren to show they’re still in the hunt for a nomination that has been slipping away.

Biden’s cloak of inevitability has been pierced by poor showings in Iowa and New Hampshire. His team hardly expected to win them, but coming in fourth and fifth wasn’t part of the plan. The former vice president has expressed confidence in his strength in South Carolina and in the 14 states that will vote on Super Tuesday — he remains formidable but has been trending downward, including with his firewall of African American voters, since the Iowa caucuses. The Nevada debate is his opportunity to stop the bleeding and show voters he still has the fire to win the presidency.

Warren, for her part, has a Sanders problem (with self-identified liberal voters) and a Buttigieg problem (with white college graduates). Opportunities are dwindling for the progressive firebrand to convert her wide appeal in the party to enough “first choice” voters to stake a claim to the nomination. The debate will reveal whether Warren plans to stick with her “unity” message or heed pressure from some allies to re-emphasize her true colors as a progressive warrior.

Who will seize on local issues?

Which of the candidates will attempt to reach Nevada voters by emphasizing local issues? Yes, the future of health care is a perennial issue atop the minds of Democrats everywhere, but Nevadans also care about matters close to home, like whether to store nuclear waste under Yucca Mountain. The state has one of the lowest home-ownership rates in the country, and its share of college graduates is below the national average. Expect some Democratic hopefuls to speak to these sorts of concerns, too.

And then there’s the question of how Nevadans view the most significant divisions in the primary.

A Fox News poll last month found that the state’s Democratic voters prefer a candidate who will “fundamentally change” Washington to one who will “restore the political system” to its pre-Trump state. When it comes to health care, most voters said they prefer a Medicare option (as proposed by Biden or Buttigieg) to a single-payer system that scraps private coverage (as offered by Sanders).

CORRECTION (Feb. 18, 2020, 4:10 p.m. ET): A previous version of this article misstated Tom Steyer’s qualifying status for Wednesday night’s Democratic presidential debate in Las Vegas. He has not qualified and will not be one of the six candidates on stage.