Candidates were asked right off the bat to weigh in on impeachment, and as in previous debates, discussion on top Democratic policy priorities was punctuated by candidates offering sharp criticisms of fellow rivals.
Here are some of the top moments from the debate:
Impeachment hearings carry over into debate
The debate stage was set shortly after the closing of a full day of impeachment testimony before the House Intelligence Committee, and moderators asked the candidates to dive in on the topic.
Massachusetts Sen. Elizabeth Warren was asked how she would convince her Republican colleagues to vote to remove the president should he be impeached by the House.
“The obvious answer is to say, 'First, read the Mueller report,’” Warren said. Because Congress failed to act on that report, she said, Trump felt free to break the law again.
In light of today's testimony from European Union Ambassador Gordon Sondland, Warren took a stab at what she says is corruption in politics, dinging Trump for appointing Sondland to his post after "he wrote a check." Sondland gave $1 million to Trump’s inaugural committee.
Warren said she would not appoint donors to ambassadorships, though the practice is longstanding in administrations from both sides of the aisle.
South Bend, Indiana Mayor Pete Buttigieg and Minnesota Sen. Amy Klobuchar called for holding Trump accountable. He is accused of improperly pressuring the Ukrainian government to pursue investigations into domestic politics, including into 2020 frontrunner former Vice President Joe Biden.
And Vermont Sen. Bernie Sanders said that while Trump is "likely the most corrupt president in the modern history of America," his campaign cannot only focus on it.
"We cannot simply be consumed by Donald Trump, because if we are, you know what? We’re going to lose the election," Sanders said.
Warren defends controversial policies on the rich
In past debates, Democrats opened with lengthy exchanges on health care – an issue that has divided centrists and liberals in the fields for months. This time, the candidates had a longer-than-usual debate on taxes.
Warren began by touting her two-cent tax on the wealthiest Americans. "I’m tired of freeloading billionaires," Warren said, but also noted that "doing a wealth tax is not about punishing anyone." Rather, she says, it's about asking those at the top to contribute to others.
"Our government is working better and better for the billionaires," Warren said, "and worse and worse for everyone else."
The argument drew a quick rebuttal from New Jersey Sen. Cory Booker, who called Warren’s plan "cumbersome" and difficult to evaluate.
Saying that all the Democrats on stage support universal pre-kindergarten care and bringing "a lot more revenue in this country” through closing loopholes, Booker said that, "I don’t agree with the wealth tax the way Elizabeth Warren puts it."
Warren's wealth tax is also part of her plan to fund Medicare for All. After taking heat from 2020 rivals at previous debates for dodging the question of how she would fund for the policy, Warren released a plan that she says would not raise taxes on the middle class.
Sanders and Warren defended their Medicare for All approaches while Buttigieg and Biden argued people shouldn’t be forced into one government-run plan.
Sanders recycled one of his biggest applause lines from a previous debate during the health care discussion.
After Warren talked about the need for reform, the debate moderators gave Sanders a chance to respond.
“Thank you,” Sanders quipped. “I wrote the damn bill.”
It was a line that Sanders first rolled out during a debate in July in Detroit when challenged about the details of his health care plan.
“The vast majority of Democrats don’t support Medicare for All,” Biden said, asserting that it couldn’t pass the Democrat-controlled House. Biden supports a Medicare option that builds on the Affordable Care Act, and says that people don't want to lose their current health insurance plans.
“I trust the American people to make a judgement that they believe is in their interest," Biden said.
Gabbard prompts brawl with dig at Democratic Party
Candidates were at each other's throats early on in the November Democratic debate. In one instance, it started with Hawaii Rep. Tulsi Gabbard taking another swipe at the Clintons.
It ended with a broader debate about the future of Democratic foreign policy and whether, as Gabbard claims, the party needs to break with the past.
Asked to explain a Twitter firestorm between Gabbard and 2016 Democratic presidential nominee Hillary Clinton last month, Gabbard said that the party needs to break away from the “Bush-Clinton-Trump” foreign policy that she described as being driven by “greedy corporate interests.”
That drew a response from California Sen. Kamala Harris, who accused of Gabbard of spending “four years on Fox News criticizing Obama.”
“What we need on this stage,” Harris said, “is someone who has the ability to win.”
Gabbard said that Harris continued to “traffic in lies and smears and innuendos because she cannot challenge the substance of the argument that I'm making, the leadership and the change that I am seeking to bring.”
What started it? Clinton’s comments to a podcast last month were initially erroneously reported as her saying Russians appeared to be "grooming" Gabbard. Clinton had actually said it was the Republicans who were "grooming" Gabbard, according to an aide.
But Clinton also said in the podcast that "She's a favorite of the Russians" and continued to also talk about former Green Party candidate Jill Stein.
Gabbard shot back on Twitter, calling Clinton the "queen of warmongers, embodiment of corruption, and personification of the rot that has sickened the Democratic Party for so long."
Stabs at rivals masked in quips and jokes
Quick wit served several candidates on stage as they sparred with each other over policy issues, prompting laughter and applause from audience members and spreading widely on social media.
And as Trump's rapid response team fired off emails to counter Democrats' points, they also fired off quips aimed at the president.
Booker slammed Biden for saying this week that he was not prepared to support legalizing marijuana, tying it to the disproportionate effect drug laws have had on communities of color. African Americans have faced a harsher application of those laws than white Americans.
“I thought you might have been high when you said it,” Booker said to Biden.
Biden said he supports decriminalizing marijuana, but said Americans should study the long-term effects of the drug before legalizing it. His earlier comments included that marijuana may be a "gateway drug."
That view has puts Biden at odds with a significant share of voters of both parties, according to polls.
Booker also used a question about how he would unify the country to get in a subtle dig at Buttigieg.
Asked how he would bring the country together if he is president, Booker said the nation achieves great things “when we stand together and work together.” He went on to cite his work as mayor of Newark, N.J., as an example.
“I happen to be the other Rhodes Scholar mayor on the stage,” Booker declared.
The quip was a clear reference to Buttigieg, who has overshadowed Booker and other Democratic candidates in the polls for much of the campaign.
Buttigieg’s rise – some polls put in him in first place in Iowa and New Hampshire – has rankled some of his Democratic rivals.
And entrepreneur Andrew Yang got a good laugh – and applause – when asked what, if elected president, he would say in his first call to Russian President Vladimir Putin.
“At first, I’d say I’m sorry I beat your guy,” Yang said, taking a stab at Trump. Then he quickly added: “Sorry, not sorry.”
The return of Biden's gaffes
Before the debate even began, the Biden campaign mistakenly sent an email to supporters that was meant to go out after the debate had ended. "I hope I made you proud out there," the email said.
But that wasn't the end of it, as Biden turned some heads with comments he made on stage, after a respite in his notorious verbal flubs in public appearances.
Looks like Biden’s campaign has accidentally sent a post-debate fundraising email out early. It suggests he may target Warren again tonight.— Jess Bidgood (@jessbidgood) November 20, 2019
“We need more than plans... We need to reach across the aisle and demand that our leaders do what’s right.” pic.twitter.com/7YSvzy1bGm
Biden’s response to how he would address sexual violence drew laughter for an unfortunate choice of words. He started by reminding the audience he authored legislation to address violence against women.
He argued that “No man has a right to raise a hand to a woman in anger other than in self-defense, and that rarely ever occurs.”
“So we have to just change the culture, period,” Biden said, but then added. “And keep punching at it and punching it and punching at it.”
The former vice president also touted his support from African Americans, one of the reasons he’s leading the field in South Carolina while lagging behind the other frontrunners in Iowa and New Hampshire.
“I have more people supporting me in the black community,” Biden said, then saying that he was endorsed by "the only African American woman who'd ever been elected to the United States Senate," likely referring to Carol Moseley Braun. The Illinois woman, the first black woman elected to the Senate, served a single term in the Senate during the 1990s.
“That’s not true,” both Booker and Harris interjected.
“The other one is here,” Harris said of herself, incredulously, as the stage erupted and Biden quickly tried to correct by saying he meant to say "the first," black woman elected.
Contributing: Nicholas Wu, Maureen Groppe, John Fritze, Michael Collins
This article originally appeared on USA TODAY: 2020 Democrats: Top moments from the November debate in Atlanta