Democratic debate in Nevada

Sen. Elizabeth Warren attacked former New York City Mayor Mike Bloomberg tonight on the stage in Nevada, calling him a substitute for "one arrogant billionaire."

Warren added: "Democrats 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 red lining and stop and frisk. Look, I'll support whoever the Democratic nominee is, but understand this, Democrats take a huge risk if we just substitute one arrogant billionaire for another."

Michael Bloomberg has faced scrutiny for his implementation of stop and frisk, which was a policing tactic that allowed officers to detain a person on any type of vague suspicion, search that individual without a warrant and arrest the person if any kind of illegal substance or weapon was found.

Stop-and-frisk searches peaked under Bloomberg at 203,500 stops during the first three months of 2012. The practice was cut back amid protests and lawsuits.

Bloomberg has apologized for implementing it.

The six presidential candidates are now taking the stage at tonight's Democratic debate in Las Vegas, Nevada.

You can follow CNN’s live debate coverage here or on CNN.com

Joe and Jill Biden are taking three Nevadans personally impacted by gun violence as their guests to tonight’s debate in Las Vegas, a campaign official says.

Biden has sought to bring gun control front and center at his events in Nevada this week.

These are his guests tonight:

Democratic presidential candidate Sen. Bernie Sanders is well ahead of the rest of the field for the Democratic national primary after strong showings in Iowa and New Hampshire, according to a new CNN Poll of Polls on the race.

Sanders, a Vermont independent, is leading the pack as the candidates head to the Nevada caucuses with 28% of support among registered Democrats and Democratic-leaning independents or likely Democratic voters.

Here's where the other candidates stand:

The poll of polls includes an average of the five most recent nonpartisan, live operator, national surveys on the race for the Democratic presidential nomination conducted among registered voters who either consider themselves Democrats, Democratic-leaning independents or likely Democratic voters. The surveys were conducted after voting in the Iowa caucuses began on February 3.

Sanders takes commanding lead in CNN poll of polls:

Former Vice President Joe Biden was asked how he will debate Mike Bloomberg on the stage during a hectic Culinary Union picket line outside of the Palms Casino Resort today.

After saying he will tell “the truth,” Biden expanded that the truth is that Bloomberg has “basically been a Republican his whole life.” Biden continued that he didn’t endorse either him or President Barack Obama and said that he’s going “to talk about his record.”  

Asked if he believes the Bloomberg ad featuring Obama is disingenuous, Biden replied, “Mildly, mildly.”

Biden admitted tonight is important to “reviving his campaign.” Asked by a reporter, he replied, “I think it’s really important, I think we’re gonna do well.” 

Asked if he was going to “come out swinging,” Biden responded, “We’ll see.”

Other Democratic candidates Elizabeth Warren, Pete Buttigieg and Amy Klobuchar also visited the picket line Wednesday.

Hear more from Biden’s Deputy Campaign Manager: 

Six presidential candidates will face off tonight in Las Vegas, days before the Nevada caucuses.

The debate will air live at 9 p.m. ET from the Paris Theater in Las Vegas.

It will air live on NBC News and MSNBC. It will stream on NBC and MSNBC web and mobile platforms, and on The Nevada Independent's website. The debate will air live in Spanish on Universo, as well as the Noticias Telemundo mobile app and website and Noticias Telemundo's Facebook page, according to NBC.

You can also follow CNN’s live debate coverage here or on CNN.com

The early voting turnout in Nevada could be around 70,000 ballots, a Nevada Democratic Party aide tells CNN.

The party is still counting ballots from Tuesday, the final day of early voting, but the aide believes the final turnout for the day could be around 33,000 — nearly equivalent to the 36,000 ballots that were cast on the first three days of early voting.

Roughly 84,000 Nevadans participated in the 2016 caucuses, which had no early voting.

How early voting works: When a voter walks into an early voting site, they check in with an election volunteer who has a PDF voter roll pre-loaded onto an iPad. If a voter is not a registered Democrat, they will need to register with the party at that time.

The voter, after being given a pre-generated voter PIN, is asked to enter their information into a check-in form via Google.

The voter, once they begin the actual voting process, is then asked to rank either their candidates one to five in order of preference on a ballot.

That preference list is unique to caucuses and is done so that if the voter's top choice does not reach viability in their caucus site on caucus day -- that means they usually have 15% of the room supporting them -- their support can go to their second or third choice. Voters can express support for up to five choices in ranked order. For example, if a voter who voted early puts former Vice President Joe Biden as their top choice but Biden is not viable in their caucus site on Saturday, their second choice will be counted upon realignment.

The voter, once finished, signs their ballot.

Michael Bloomberg, the billionaire former New York City mayor and potential 2020 presidential candidate, announced Wednesday that he re-registered as a Democrat, saying the party must "provide the checks and balances our nation needs so badly."

"At key points in U.S. history, one of the two parties has served as a bulwark against those who threaten our Constitution," Bloomberg wrote in an early morning Instagram post.

"Two years ago at the Democratic Convention, I warned of those threats. Today, I have re-registered as a Democrat — I had been a member for most of my life — because we need Democrats to provide the checks and balance our nation so badly needs."

A Bloomberg spokesman declined any further comment.

Bloomberg, who was elected mayor as a Republican and an Independent, has been toying with the idea of running for president in 2020 as a Democrat. In September, he told The New York Times that if he were to run in two years, it would only be on the Democratic ticket.