When six Democratic presidential candidates meet for a televised debate Wednesday night in Las Vegas – joined for the first time by former New York City Mayor Mike Bloomberg – each will face his or her own set of challenges and vulnerabilities.

Bloomberg – with a fortune estimated at over $60 billion – is spending hundreds of millions of dollars of his own money on ads and staff across the nation. He has become one of the top competitors despite not being on the ballot in the first four nominating contests in Iowa, New Hampshire, Nevada and South Carolina, and despite entering the presidential race late.

In addition to Wednesday’s debate in Las Vegas, Bloomberg has qualified to participate in another debate Tuesday in South Carolina, thanks to his strong showing in the polls.

'SOCIALIST' SEEN AS MOST UNPOPULAR QUALITY IN PRESIDENTIAL CANDIDATE, POLL FINDS

According to a Wall Street Journal-NBC News national poll published Tuesday night, the candidate drawing the most support from likely Democratic primary and caucus voters is Sen. Bernie Sanders of Vermont with 27 percent.

Sanders is followed by former Vice President Joe Biden with 15 percent; Bloomberg and Sen. Elizabeth Warren of Massachusetts with 14 percent; former South Bend, Ind., Mayor Pete Buttigieg with 12 percent; and Sen. Amy Klobuchar of Minnesota with 7 percent.

Because of the margin of error in the poll, Biden, Bloomberg, Warren and Buttigieg are bunched up in what amounts to a statistical tie for second place.

In the debate Wednesday night, we can expect the gloves will come off as candidates attack each other to fight for their breakthrough moments.

Bloomberg will no doubt get plenty of attacks as a billionaire spending record amounts to buy his way to the White House.

Warren previewed this line of attack Tuesday when she tweeted: “It’s a shame Mike Bloomberg can buy his way into the debate. 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.”

And as the leader in polls, Sanders is sure to be attacked for being too far left to win a general election. He proudly calls himself a democratic socialist, but many voters tell pollsters they won’t support a socialist for president.

So what does each of these candidates have to do in the Wednesday night debate? What should each prepare for?

Mike Bloomberg

Bloomberg is focusing much of his campaign against President Trump, as if he is already the Democratic presidential nominee. In the battle to become the nominee, the former New York City mayor is contrasting himself to Sanders, positioning himself as a moderate with virtually unlimited funds who is better able than the socialist senator to defeat Trump in November.

Bloomberg is going to have to respond Wednesday night to the criticism by his fellow candidates that he is using his enormous wealth to buy the presidency with a massive nationwide advertising campaign.

The billionaire businessman and former mayor is also going to have to once again explain his support for the stop-and-frisk police tactic, which disproportionately impacted black and Latino men in New York City. He has already apologized several times in recent weeks for the anti-crime initiative, saying he did not realize years ago how harmful and racially discriminatory aspects of stop-and-frisk were.

Bloomberg will also have to fend off attacks accusing him of making racist comments and profane and sexist comments to and about women.

Nevertheless, the debate will give Bloomberg the chance to stand alongside the other major Democratic presidential candidates and speak for more than the few seconds of a TV ad.

Joe Biden

The former vice president needs to win the Nevada caucuses Saturday, or at least come in second. He also needs to win the South Carolina primary a week later to make up for his poor showing in the Iowa caucuses and New Hampshire primary.

To achieve these goals Biden needs a strong debate performance Wednesday night, with a breakout moment.

Biden, who has long enjoyed strong support among the African-American community, needs to attack Bloomberg for the former mayor’s record on race, particularly since polls show Bloomberg is gaining increasing black support, including endorsements from black elected officials.

Biden has said he is the Democrat with the greatest chance of defeating Trump in November. But that label won’t stick if he continues to run poorly in caucuses and primaries.

As a result, Biden will be fighting for his political life in the Nevada and South Carolina debates. The former vice president’s standing in national polls has ticked lower as Bloomberg has risen in the polls.

Bernie Sanders

Polls indicate Sanders has more support among Democrats in Nevada – about 25 percent – than any of his competitors. He is gaining increasing popularity among Latino voters on a national level as well as in Nevada.

Sanders needs to alleviate the fears of many Democrats that he will split the Democratic Party. Although he has stated he would support whomever the Democratic nominee is, many people don’t believe him, recalling the bitter campaign between him and Hillary Clinton for the Democratic presidential nomination four years ago.

The failure of some Sanders supporters to vote for Clinton in the general election helped elect Trump as president.

Sanders should expect to be attacked Wednesday night for being a self-described democratic socialist, and face accusations that he is supporting unaffordable, impractical and ineffective solutions to the problems facing the nation today.

It’s also possible that someone will bring up the 78-year-old senator’s health, particularly since he suffered a heart attack recently on the campaign trail. Is he physically up to the high-pressure job of being president? He should be prepared to respond.

Pete Buttigieg

The 38-year-old former mayor of South Bend, Ind., did very well in both Iowa and New Hampshire – two states with an overwhelming majority of white voters.

Nevada and South Carolina will show what Buttigieg can do in states with large Latino and black populations that more accurately reflect the demographics of the nation and the Democratic Party.

So far Buttigieg has been unable to answer for shortcomings in his dealings with the black community when he was mayor of South Bend. He needs to do a better job Wednesday night.

The former mayor also needs to deal with criticism that he is too young and inexperienced to go from being mayor of a small city to the White House without any experience in national or even state government. Of course, Trump had no government experience when he was elected either.

Amy Klobuchar

Klobuchar hit it out of the park at the last debate in New Hampshire, delivering by far the best performance among the Democrats on stage. That stellar performance led to more money and more support among voters.

But voters are fickle. They’re looking for a leader and someone who can beat Trump.

Like Buttigieg, Klobuchar needs to improve her standing among African-American and Latino voters. And she needs to be prepared to answer for the fact that she has voted with Trump in Congress more than any other Democrat on the stage. Saying she’s truly bipartisan isn’t going to cut it with the Democratic voters.

Elizabeth Warren

Warren is the “I’ve got a plan for that” candidate. But what she doesn’t seem to have a plan for winning nominating contests, as we saw with her poor showings in Iowa and New Hampshire, a state that borders her home state of Massachusetts.

CLICK HERE TO SIGN UP FOR OUR OPINION NEWSLETTER

Warren typically does very well and is quite strong at the debates, but she needs to be able to turn a strong debate performance in strong showings in Nevada and South Carolina.

The senator from Massachusetts might come under attack for her proposed wealth tax by Bloomberg, who is one of the richest people in the world. Even many voters who believe the rich should pay higher taxes believe the wealth tax goes too far.

Warren also needs to explain how her positions differ from socialist Sanders on the far left and the other more moderate candidates to her right, and show why her positions deserve voter support.

CLICK HERE TO GET THE FOX NEWS APP

Millions of gamblers who visit Las Vegas each year wind up losing money. Some of the candidates on stage in Las Vegas Wednesday night could wind up losing their chance to be president if they perform poorly in the debate.

They say what happens in Vegas stays in Vegas. But all the candidates in the debate will be doing their best to see that their candidacies don’t end in Vegas, but instead survive the debate and the Nevada caucuses so they can continue their campaigns for the White House.

CLICK HERE TO READ MORE BY LESLIE MARSHALL