Gabbard got the first climate change question of the night and said that it’s an issue that transcends political party and everyone should come together to break the hyperpartisanship to get climate policies passed 

Steyer called out Biden and Warren — two of the front-runners — saying it is a No. 1 priority for him unlike those two. He said that, on Day One of his presidency, he would declare a state of emergency and make climate change part of his foreign policy.

Biden shot back saying that he has been on the front line of climate change and attacked Steyer for operating coal mines while he was working on climate policy. Steyer responded by saying everyone on the stage lived in an economy based on fossil fuels and he came to a conclusion to avoid them a decade ago. 

Sanders says that he would go directly after the fossil fuel industry and said they are criminally liable because they had “evidence” that their products hurt the environment. 

An hour and change into the Democratic debate, Tom Steyer has made 6 fiery attacks. He's only spoken for 5 minutes. 

His latest: "I’m the only person on this stage who will say that climate is the No. 1 priority for me. Vice President Biden won’t say it. Senator Warren won’t say it."

Follow our live tracker of how who's speaking the most (and least) during the debate tonight and see who's attacking who.

Conventional wisdom heading into Wednesday’s debate was that the candidates, who had started to telegraph hits on Buttigieg along the campaign trail, would go after the surging candidate.

But as polls show Buttigieg rising to first in Iowa and New Hampshire, no one’s taken a direct shot at him in  the debate’s first hour. Even Klobuchar, asked about her previous criticism of Buttigieg, demurred.

But of note, there’s been little fighting on stage through the debate so far.

Buttigieg was just asked about farm subsidies — a closely watched issue in largely rural, first-to-caucus Iowa, where polls show him absolutely surging.

It’s no surprise, then, that Buttigieg says that he would continue farm subsidies, although he notes that such payouts are not making farmers “whole.”

There were 33 attacks in the first 60 minutes of tonight's debate, and 16 of those were aimed at President Donald Trump.

Here's how the NBC News debate attack tracker looks at the halfway mark of tonight's debate.

Steyer hasn’t been much of a factor tonight but he offers a strong and differentiated answer on the U.S. housing crisis. 

He says there needs to be changes in policy and an influx in resources “to build literally millions of new units.” But Steyer adds another element — sustainability — noting that where people live has an impact on the climate.

Warren also gets in an answer, putting the issue squarely on the need for more housing. She touts her plan for 3.2 million new housing units and notes that housing is a sustainability issue. 

“The federal government has subsidized housing for decades for white people,” Warren said, while declining to do so for black Americans. “That’s called redlining”

For his part, Booker called out gentrification, which he said involves “low-income families moving farther and farther out, sometimes compounding racial segregation” and proposed a tax credit that would subsidize renters in the same way the federal government subsidizes homeowners.

Amidst a nationwide homelessness crisis, one candidate missing from the stage tonight made his absence known on Twitter: former Secretary of Housing and Urban Development Julián Castro, who subtweeted the proceedings:

On the 2020 campaign trail and during his White House tenure, Castro has been a forceful voice speaking out against homelessness and various forms of housing inequality.

“I have proposed a 2-cent wealth tax,” Warren said on Wednesday night. “Your first 50 billion is free and clear — but your 50 billionth and first dollar, you gotta pitch in 2 cents, and when you hit a billion dollars, you gotta pitch in a few pennies more.”

First, Warren misspoke here in the first part of her wealth tax plan. She meant to say "the first $50 million," not $50 billion. We know because it's how Warren’s been pitching her wealth tax for weeks — your first 50 million dollars are "free and clear," but once you hit 50 million and one dollar, a wealth tax of 2 cents kicks in.

It sounds simple, right?

Well, it’s not really. Yes, the tax is 2 cents on the dollar of assets over $50 million and 6 cents of every dollar over $1 billion. (She recently hiked that top bracket from 3 cents on every dollar above a billion to 6 cents, to pay for her health care plan.) 

But, this tax is applied annually, so it would keep wealth from growing in many cases and act like an income tax in many ways. Wealthy investors with assets seeing a 6 percent return annually, for instance, would essentially see a 100 percent tax on those assets.

It may sound like pennies, but the dollars add up big time: Two economists who advised Warren estimated recently that if her wealth tax had been in effect since 1982, Bill Gates’ wealth would be a fraction of what it is now.

There's one notable shift in focus in tonight’s Democratic debate when compared to its predecessors. So far tonight, Trump’s conduct is front and center as the impeachment probe proceeds.

Candidates fielded early questions on the impeachment probe, Americans chanting “lock him up,” and whether, if elected president, they would prosecute Trump after he leaves office. A sharp contrast from earlier debates when the first hour consisted of mostly debating the candidates’ stances on health care policy.

In 2013, before the major elements of the Affordable Care Act went into effect, more than 44 million Americans lived without health insurance, according to an analysis of census data conducted by the Kaiser Family Foundation.

After Obamacare began, the number of uninsured Americans sank to a historic low of 26.7 million people, about 10 percent of the nation’s population. Then, after a series of changes were made to the Affordable Care Act,  the number of uninsured Americans rose. In 2017, 27.4 million people were uninsured, marking the first time since Obamacare began that the ranks of the uninsured expanded.

While most Americans are insured, the share who also fall into the ranks of the underinsured remains significant. The Commonwealth Fund, a foundation which among other activities researches health care topics, defines the term underinsured to include anyone whose health insurance deductibles and other out of pocket costs eat up 5 to 10 percent of their total income. Such a situation can make medical bills and prescription drug costs difficult to cover, force people to contemplate skipping much needed doctor visits, avoid emergency room care and to make other choices which can compromise their health. 

The share of Americans with insurance provided by an employer who are also underinsured grew from 17 percent in 2010 to 28 percent in 2018, according to the Commonwealth Fund. The figures are even larger for those who purchase individual health insurance plans. Among individual health insurance policy buyers, 37 percent were underinsured in 2010 and 42 percent were in the same situation last year.

Sanders was asked about the “lock him up” chants recently hurled at Trump, such as at a World Series game in Washington last month.

Sanders did not disavow the chants, a mirror of Trump supporters cheering “lock her up” about Hillary Clinton in 2016. Sanders said simply that he thinks “the people of this country are catching on to the degree this president thinks he is above the law.”

Biden said that he would not prosecute Trump after he leaves office because it’s not his job to decide who would be prosecuted or exonerated. He said it’s the attorney general’s decision, and if the independent conclusion was to pursue prosecution, then “so be it.”

He argued that the attorney general is not the president’s attorney.

Sen. Amy Klobuchar, responding to questions over her recent criticism of Buttigieg (she said earlier this year that if female candidates like herself had the amount of experience that Buttigieg did they wouldn’t be taken as seriously as he is), backed down on her assessment — but still delivered a sharp line about gender that got the audience’s attention.

“First of all I made very clear that I think Pete is qualified to be on this stage,” she said. 

“But what I said was true,” she added. “Otherwise, we could play a game called ‘name your favorite woman president.’”

She closed her answer with another line that prompted loud applause from the audience.

“And if you think a woman can’t beat Donald Trump, Nancy Pelosi does it every single day,” she said.

Yang hasn’t gotten much screen time, but he did get the attention of the tech crowd.

He advocates bringing back the Office of Technology Assessment, which helped advise on technology policy until it was defunded in 1995. But bringing back the OTA, as it was colloquially known, already has some supporters in Washington, D.C. — and among the technorati.

Which candidate is speaking the most at tonight’s debate in Atlanta? Who's speaking the least? NBC News is collaborating with The Washington Post to track how long each candidate talks throughout the night. Follow along here.

Buttigieg said he sees "extraordinary potential" to enact big policies now that were politically impossible a few years ago.

“We have a majority to do the right thing, if we can galvanize, not polarize, that majority," Buttigieg said when asked how he would overcome the partisan fighting that ground Barack Obama's agenda to a halt.

But in his first two years, Obama had majorities in the House and Senate, including a filibuster-proof supermajority in the Senate for a moment, that a hypothetical President Buttigieg would be unlikely to get.

The Senate is currently controlled by Majority Leader Mitch McConnell, R-Ky., who has made the chamber a "legislative graveyard" for Democratic bills. Even if Democrats win back the Senate next year, they're highly unlikely to get the 60 votes they would need to break a GOP filibuster. And while Buttigieg has said he wants to scrap the filibuster, many Democratic senators oppose doing so.

So Buttigieg didn't really explain why he would succeed where Obama didn't.

Harris went directly after Gabbard, saying that she spent four years under Obama on Fox News trashing the Obama administration, “buddied up to Steve Bannon” to get a meeting with Trump and cozied up to a war criminal — an apparent reference to Syrian President Bashar al Assad. 

This attack was one of the sharpest yet. Harris said that Gabbard doesn’t have the goods to take on Trump and reunite the Obama coalition to win the election. 

Gabbard shot back by saying Harris is trafficking in lies and was not dealing with the substance of her argument, which is that the Democratic establishment is out of touch. 

"The president had to confess in writing, in court, to illegally diverting charitable contributions that were supposed to go to veterans," Buttigieg said Wednesday night, responding to a question about impeaching President Donald Trump. 

This is mostly true. The president did admit to illegally misusing the Trump Foundation — in particular the $2.8 million raised for veterans in an event in Iowa days before the 2016 caucuses — in a court filing. Those dollars were controlled and disbursed by Trump’s campaign staff at campaign events, instead of being overseen by the Foundation. But, the money was eventually donated to charitable causes.

For her first question of the night, Gabbard was asked about the “rot” she says Clinton inflicted on the Democratic Party. Gabbard said the party “continues to be influenced by the foreign policy establishment represented by Hillary Clinton and others.”

Gabbard began to surge slightly in the polls after Clinton attacked her publicly, with Gabbard capitalizing on the comments in numerous responses.

Booker, who has moved closer to the stage’s edge, had the first direct attack on Warren’s wealth tax plan. He’s talking about minority communities wanting the opportunity for entrepreneurship and said that they don’t just want equality in wealth, but equality in opportunity. He seems to go directly after Warren’s goal to restructure the American economy to help the working class.

He called the wealth tax “cumbersome” and said that Democrats need to talk about how we tax wealth but also grow wealth across the country.

Yang, Steyer and Gabbard aren’t getting any speaking time early. Twenty minutes in and the three candidates have yet to be asked a question.

We're publishing two live-updating graphics tonight to capture what's happening as it happens on the debate stage in Atlanta.

The attack tracker: We're tracking the number of times the candidates on the stage attack each other, and attack President Donald Trump.

The time talking tracker: We're partnering with The Washington Post to show how long each candidate has spent talking through the night.

In his first answer of the night, Biden said the impeachment hearings have made clear to him that Trump and Russian President Vladimir Putin don’t want him to be the Democratic nominee.

“Trump doesn’t want me to be the nominee,” Biden said, pointing to the House inquiry into the withholding of aid to Ukraine as the president pushed for an investigation into the former vice president and his son Hunter.  And “Vladimir Putin doesn’t want me to be president,” Biden added.

Biden argued that the most important consideration for Democratic voters in the race is to choose a nominee who can beat Trump, secure a Democratic majority in the Senate and increase the number of House Democrats. He says that’s him.

After Sondland’s testimony, Harris said that “justice is on the ballot” because the president has been running a “criminal enterprise” and impeachment is part of holding Trump accountable. 

But she also wrapped her answer around inequality in the country, where the rich and powerful break the law with impunity. And she wants to hold them accountable as president. 

Noting that tonight’s debate comes just hours after a jampacked day of public testimony in the House Democrats’ impeachment inquiry, the first question directed at the candidates, aimed at Sen. Elizabeth Warren, D-Mass., was about whether she’d try to convince her colleagues in the Senate that President Donald Trump deserves to be convicted, if the House impeaches him.

“Of course I will,” she said.

Ahead of tonight’s debate, Biden has tweeted a thread outlining exactly what he means when he says America is in a “battle for the soul of this nation.”

It’s a development we’ve seen on the campaign trail in recent weeks where Biden has said that the battle isn’t just one about defeating President Donald Trump, but a personal battle for those facing economic hardships. 

In tonight's thread, he goes further saying the "soul of the nation" means improvement on different fronts and how he is the only one who can get that done — a good preview of what he’s expected to say tonight. 

You can add Ariana Grande to the list of celebrities "feeling the Bern."

The Sanders campaign tells NBC News that Grande and her mother, Joan, met with the senator and his wife before Grande went on stage at State Farm Arena in downtown Atlanta Tuesday night. 

The campaign says Sanders was "super impressed" with her work registering young people to vote. According to Grande's post on Twitter, her team has registered more than 20,000 young people to vote at her concerts.

Grande has been politically active all year. In July, she attended a California fundraiser for Sen. Kamala Harris at music producer Scooter Braun's house.  

Student debt has surged in recent years and now stands at over $1.6 trillion.

Some Democrat candidates are proposing tuition-free public college and canceling student debt, while others are offering more limited benefits. Critics say many of the initiatives would benefit disproportionately better-off Americans.

What the candidates (including Trump) are proposing.

Buttigieg is proving once and for all that "Boomer" isn't just a generation, it's a state of mind.

Videos have flown around the internet in recent days featuring a choreographed dance being performed by his supporters. It’s set to “High Hopes” by Panic! At the Disco. 

The dance has also triggered something of a backlash on the teen-heavy TikTok, where young politicos are using it to critique Buttigieg’s centrist positions.

Viewer discretion advised.

Ahead of the debate, people submitted their confessions about the 2020 candidates live from Atlanta. See the most recent confessions and share your own.

Stacey Abrams won't be on the debate stage when the Democratic presidential candidates face off in Atlanta on Wednesday, but that doesn't mean she won't be playing a role in the 2020 elections.

Since Abrams' loss to Republican Brian Kemp in the Georgia governor's race last year, she's worked to combat voter suppression, which Abrams alleges cost her the race. Ahead of the presidential election next year, Abrams is using her political action committee, Fair Fight, to repair what she believes to be a broken voting system in her state.

"My reaction to the mismanagement and the malfeasance was to think about what could I do, not simply about my election, because that was over, but what work could I still do that would address the challenges that so many Georgians faced in that process?" Abrams told NBC News.

A group of 35 students from Georgia State University in Atlanta joined NBC News to help produce Wednesday night's Democratic debate.

Each student was selected by their professors to apply for the opportunity and underwent an interview process with both their professors and NBC.

The students, a mix of undergraduate and graduate students, were selected to portray candidate stand-ins during rehearsals, hand out credentials, and work behind the scenes to help NBC put on the broadcast.

David Howell, a junior journalism major and political science minor was tasked with playing Joe Biden during rehearsals. He said that he made sure to heavily prepare for the role beforehand,

"I did all sorts of research, the majority came from watching videos [of Biden in] prior debates and reading Twitter posts where he talked about policy," he said.

Kyle Smith, a graduate student working towards a master's of art and communication with a focus in digital media strategies, has been assisting with handing out credentials to members of the media. He said that he jumped at the experience due to the importance of the upcoming election.

"This is a huge election because our voice matters. We need numbers in order to make change happen in Georgia, which is primarily a red state," he said.

Noorma Ckhoul, a senior majoring in journalism with a political science minor, played one of the moderators.

She said that while "none of us really knew what we were getting into,” the students ended up getting valuable public speaking and communications experience.

Ada Wood, a junior journalism major, said she was thrilled to have been selected to participate.

"I learned a lot about what it really takes to put on an event this big," she said. "All the hands and the people involved. All the technology."

ATLANTA — Even though he would not be onstage at the Democratic debate in Atlanta on Wednesday night, presidential candidate Julián Castro spent the morning in the city anyway touring a neighborhood founded by slaves whose residents are now fighting gentrification.

Castro, the former Housing and Urban Development secretary under President Barack Obama, toured the neighborhood, named Pittsburgh, that was founded in 1883, making it one of the oldest in the city and where many of the neighborhood's residents have lived for decades.

Although he joked he had gone to the neighborhood because that's where the media was, Castro said his visit was a continuation of what his campaign has been about.

"From the very beginning of this campaign, I've spoken out for the most marginalized, the people that have been forgotten, for the poor and not only the middle class, but people who are poor in this country and spoken out to make sure everyone can succeed, a country where everyone counts," Castro said. "And so we're going to go where we have the opportunity to deliver that message."

Full story here.

Buttigieg may have won over many members of the mostly white political commentariat in New York and Washington, and recent polls of Iowa’s overwhelmingly white electorate put him at or near the front of the crowded Democratic field there. But, at the start of October, a poll in The Charleston Post and Courier found Buttigieg had no black voter support in the state and just 4 percent support overall.

That has left two questions generating a stream of television commentary, social media memes and heated disputes. How much of Buttigieg’s difficulty with black voters, and in many cases religious voters, is because of his sexuality? And, given that black voters make up about 20 percent of the Democratic Party’s base nationwide, why is he still considered a serious contender for the nomination when he doesn’t have black voters’ support?

Read more about why black voters aren't sold on Mayor Pete.

Activist Ady Barkan endorsed Sen. Elizabeth Warren this morning ahead of the Democratic debate in Atlanta. Barkan shared his endorsement through an article in the Nation and on social media, saying that his choice was between Warren and Sen. Bernie Sanders.

“Elizabeth Warren is the individual who I believe would make the best president,” he writes. Barkan interviewed several presidential candidates in video pieces that were highly shared on social media — his voice in the conversation on health care and activism is a powerful one.

He goes on to share his admiration for Sanders and adds that Warren’s moral clarity and her funding plan for "Medicare for All" as well as her transition plan added to his decision to endorse her.

Here's more about Barkan's advocacy:

The Biden campaign corrected itself after blasting out a post-debate email hours early, blaming the misfire on being "so excited" for the matchup that they "accidentally hit send too soon."

"You might have just gotten an email from Joe about just getting off of the debate stage. That’s our bad, team," the new email said.

The initial email blast was noted on Twitter. 

There's a new front-runner in Iowa as the Democratic presidential candidates meet in head-to-head competition for the first time in more than a month at Wednesday night's MSNBC/Washington Post debate in Atlanta — but the national nomination picture is still stable.

Mayor Pete Buttigieg of South Bend, Indiana, riding a surge powered by his last debate performance and the cash he's pumped into building field operations in early states, has a 2.2-point edge over Sen. Elizabeth Warren, D-Mass., in the Real Clear Politics average of Iowa caucus surveys, with former Vice President Joe Biden and Sen. Bernie Sanders, I-Vt., trailing both of them.

At the national level, though, the standings haven't changed much. Biden's lead has narrowed to a 6.7 percent margin over Warren — 27 percent to 20.3 percent — in the Real Clear Politics average, with Sanders at 18.8 percent and Buttigieg at 8.3 percent.

This combination of campaign inertia and the failure of any one candidate to take a commanding lead after nearly 11 months of campaigning has helped convince two new candidates to enter the race, or consider doing so, in the last couple of weeks — former Massachusetts Gov. Deval Patrick, who is in, and former New York Mayor Michael Bloomberg, who may be — although neither had enough time to qualify for Wednesday's debate.

Read more here.

The Biden campaign continues to exude confidence even as Biden — who is 77 years old today — has seen his frontrunner status challenged nationally and in the early states, arguing that he remains resilient with a large bloc of supporters who believe he can beat Trump.

In a pre-debate briefing with reporters, senior campaign advisors described this time period in the election as voters “dating” the candidates, exploring their options in the field. But ultimately they’re confident they’ll be “marrying” Biden. 

Democrats, often prone to fretting about elections, have been increasingly worried that their large and divided presidential field, currently led by four imperfect front-runners, doesn't have what it takes to beat President Donald Trump next year.

They worry that Biden is too old and stumbling; that Buttigieg is too young and too inexperienced; and that Warren and Sanders are too far left and can't win. And they tend to write off the rest of the field, assuming that if those contenders haven't caught on yet, they never will.

That angst reached a fever pitch this week and helped push one new candidate and another potential challenger from the party's more moderate wing into the race — former Massachusetts Gov. Deval Patrick, who announced he's running, and former New York City Mayor Michael Bloomberg, who's thinking about it — just ahead of a New Hampshire filing deadline, which essentially barred the door to new candidates when it expired at 5 p.m. on Friday.

Read more about voters' fears here.

If the past debates are any indication, Wednesday night could feature discussions about health care, immigration, gun control and foreign policy.

With 10 candidates on stage, it can be hard to keep track of where each one stands. Luckily, NBC News has you covered.

Here's where the candidates stand on key issues.

Here are the 10 candidates who will be on stage tonight:

• Former Vice President Joe Biden
• Massachusetts Sen. Elizabeth Warren
• Vermont independent Sen. Bernie Sanders
• California Sen. Kamala Harris
• Minnesota Sen. Amy Klobuchar
• Mayor Pete Buttigieg of South Bend, Indiana
• New Jersey Sen. Cory Booker
• Entrepreneur Andrew Yang
• Billionaire Tom Steyer
• Hawaii Rep. Tulsi Gabbard

Among those absent from the debate are Housing Secretary Julián Castro, who has qualified for all the debates until now and former Texas Rep. Beto O'Rourke, who dropped out earlier this month.

The bar to qualify for the November debate, set by Democratic National Committee, was the highest thus far.

The Democratic presidential primary debate on Wednesday will feature Joe Biden and Elizabeth Warren standing center stage, flanked by Bernie Sanders and a rising Pete Buttigieg — and will be missing a couple of familiar faces.

South Bend, Indiana Mayor Buttigieg will likely capture more attention from his fellow candidates after recent polling shows him leading the field in Iowa, while Warren can expect a barrage of questions about changes to her Medicare for All plan.

The field of 10 candidates expected to take the stage at Tyler Perry Studios — fewer than the 12 at October's debate — will be missing some familiar faces.

Here's what to expect from tonight's event.