Like a lot of events that take place in Las Vegas, Tuesday's first Democratic presidential debate is all about the numbers. Front-runners former Secretary of State Hillary Clinton and Sen. Bernie Sanders, Ind-Vt., dominate the polls and last quarter raked in $28 million and $26 million, respectively. Clinton and Sanders will join former Maryland Gov. Martin O'Malley, former Rhode Island Gov. Lincoln Chafee and former Sen. Jim Webb of Virginia on the CNN Facebook stage for the first of six debates. While Clinton and Sanders have no problem gathering crowds (and funds), the lesser-known candidates need tonight's debate to boost their poll standings.

Here is a guide to the poll data and fundraising numbers behind each Democratic candidate participating in Tuesday’s debate:

[Click here if you want to see all candidates' poll numbers and donor data compared]

Hillary Clinton Hillary Clinton speaks during a campaign town hall meeting in Dover, New Hampshire, July 16, 2015. Photo: Reuters/Brian Snyder

Hillary Clinton

In the polls?

Clinton has an impressive 19-point lead over Sanders in the polls. The former secretary of state is still the obvious front-runner despite the steady decline in her lead over Bernie Sanders since he announced his candidacy in late May. Clinton’s approval ratings have dropped to 44 percent since her high of 66 percent in April. The downward trend follows the Clinton campaign’s struggles with her likability, her email scandal and the rise of Sanders’ popularity. In the weeks leading up to the debate, there has been a slight rebound in Clinton’s numbers -- regaining an average of 4 points since late September's low. In Nevada, where the DNC’s first debate will take place, 50 percent of likely caucus voters favor Clinton.

In fundraising?

When it comes to money, Clinton is still the clear winner. Since announcing her 2016 presidential bid in April, Clinton’s campaign has raised $75 million -- nearly double what Sanders has raised so far. To put that another way, Clinton raised 37 times the amount of money Martin O’Malley did last quarter and 191 times more money than Lincoln Chafee. In addition, Clinton has about $20 million in super PAC money backing her campaign. However, her campaign announced last Wednesday it had raised only $28 million in the last three months, significantly less than the $47 million she raised from April to June.

Who is contributing?

Donors are contributing to Clinton’s campaign in larger chunks. According to an International Business Times analysis of Federal Election Commission data from April to June, nearly 12,000 of her total contributions were in donations of more than $2,000. That’s nearly three times as many as donations in the $200.01-$499.99 range. Any contribution of less than $200 does not have to be itemized, per FEC rules, which is why no such count exists. However, only $9 million of her $47.5 million haul from April to June was made up of unitemized smaller contributions. Individual donation counts for July-September are not yet available.

Bernie Sanders Sen. Bernie Sanders of Vermont speaks at the Iowa Democratic Party's Hall of Fame dinner in Cedar Rapids, July 17, 2015. Photo: Reuters/Jim Young

Bernie Sanders

In the polls?

One year ago, Sanders was barely mentioned in national polls. By May, when he announced his candidacy, he had breached the 10 percent approval rating threshold. Throughout the summer, Sanders beat Clinton in New Hampshire and Iowa polls. By the first debate, ratings for the Vermont socialist had risen to 26 percent. Despite being behind Clinton by nearly 20 points, the Sanders campaign’s momentum has excited fans and critics alike. The most recent CNN/ORC poll, however, indicated Sanders has a lot of work to do if he wants to catch up with Clinton. Only 18 percent of likely South Carolina voters "feel the Bern."

In fundraising?

Even though he is being outdone by Clinton in the money front, Sanders is still putting up quite a fight. From April to June, Sanders only raised about $15.2 million for his campaign. However, during the last three months, Sanders’ campaign said it raised $26 million, almost matching Clinton who raised only $28 million in the same period. Sanders is decidedly second, especially compared to Martin O’Malley and Lincoln Chafee. He also has refused to accept money from a super PAC.   

Who is contributing?

In contrast to Clinton, Sanders has fueled his fundraising frenzy with smaller donations. According to an IBT analysis of FEC data from April to June, more than 3,000 of his total contributions were were in the $200.01-$499.99 range. Because any contribution of less than $200 does need not be itemized, no count exists. Still, 73.1 percent of the total money raised from April to June was from unitemized smaller contributions. In addition, only 145 donors gave more than $2,000. Individual donation counts for July-September are not available.

O'Malley Democratic presidential contender O'Malley speaks during an event at the Truman Center for National Policy July 23, 2015, in Washington. Photo: Win McNamee/Getty Images

Martin O’Malley

In the polls?

O’Malley, while often listed third behind Clinton and Sanders, is currently ranked just below Webb in poll numbers. In national polls he has consistently hovered between 1 percent and 3 percent. Even in his home state of Maryland, a recent Washington Post-University of Maryland poll indicated O’Malley could muster only 4 percent of Democratic voters.

In fundraising?

Unlike Hillary Clinton and Bernie Sanders, O’Malley’s campaign did not announce his latest fundraising numbers last week. However, in the previous quarter from April to June, the campaign raised about $2 million. That’s enough to put him in third place, but still way behind Sanders and Clinton.

Who is contributing?

O’Malley, like Clinton, is depending on big money donations for his presidential bid. An IBT analysis of FEC data revealed 519 of his individual donations from April to June exceeded $2,000. Only 167 of his donations were in the $200.01-$499.99 range.  Because any contribution of less than $200 does not have to be itemized, no count exists. Individual donation counts for July-September are not yet available.

Chafee Lincoln Lincoln Chafee. Photo: Reuters

Lincoln Chafee

In the polls?

On the brightside, Chafee made it into the debate. According to criteria announced by CNN, a candidate must “have achieved an average of 1 percent in three polls, recognized by CNN, released between Aug. 1 and Oct. 10.” That is about where the good news ends for Chafee, who averaged only 0.6 percent in the past year.

In fundraising?

Compared to his counterparts, Chafee is trailing when it comes to fundraising. From April to June, the former Rhode Island governor only raised about $392,000. He loaned his campaign more than $364,000, meaning he only actually raised 8 percent from the outside. However, he announced his candidacy in early June giving him less than a month of fundraising during the second quarter.

Who is contributing?

The majority of Chafee’s few contributors tend to be in smaller donations. From April to June, he received 13 donations in the $200.01-$499.99 range compared to two donations more than $2,000, an IBT analysis of FEC data revealed. Because any contributions of less than $200 do not have to be itemized, no count exists. Individual donation counts for July-September are not yet available.

Jim Webb Democratic presidential candidate and former U.S. Sen. Jim Webb is shown speaking at the Iowa State Fair, Aug. 13, 2015, in Des Moines. Photo: Justin Sullivan/Getty Images

Jim Webb

In the polls?

Like O’Malley and Chafee, Webb’s poll numbers are consistently less than 3 percent. Five percent of Democratic voters in the former senator’s home state of Virginia said they would vote for Webb in a recent poll. However, on a national level, Webb scrapes by with only 2 percent of the vote.

In fundraising?

We don’t know yet. Jim Webb formally announced his candidacy in early July, missing the June 30 deadline. He was not required to disclose his donors to the FEC until last week. Like Sanders, Webb has also pledged not to take money from a super PAC.

ALL DEMOCRATIC CANDIDATES COMPARED