5 takeaways from the last Democratic primary debate of 2019 The candidates clashed in Los Angeles with just 7 weeks until the Iowa caucuses.

Seven Democrats vying to unseat President Donald Trump at the ballot box in 2020 took to the smallest debate stage of the cycle yet in Los Angeles Thursday night, just one day after Trump became the third U.S. president to be impeached.

With less than seven weeks until the Iowa caucuses, Thursday night’s debate featured clear shows of both unity and division among the Democratic ranks, and candidates with a firm understanding that their time to draw distinctions among their competitors is running out.

“Wine caves” and “purity tests,” and the recurring differences between the leading candidates on healthcare and foreign policy generated some of the night’s tensest exchanges -- serving as a preview of the fights that will drive the final push before Democratic voters head to the polls.

Democratic presidential candidates Andrew Yang, South Bend, Indiana Mayor Pete Buttigieg, Sen. Elizabeth Warren, former Vice President Joe Biden, Sen. Bernie Sanders, Sen. Amy Klobuchar, and Tom Steyer await the start of the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Mario Tama/Getty Images

Here are five key takeaways from the last Democratic primary debate of 2019:

Democrats grapple with impeachment’s gravitational pull

The contenders began the matchup with a question on the impeachment of Trump, forcing the Democrats to take on the pull of Washington’s most prominent issue. While all seven showed a united front on the historic vote by the House, the candidates also revealed some of their most significant distinctions on where they would take the country.

Former Vice President Joe Biden, the first candidate to step up to the plate, took up the mantle as a constitutionalist by telling the moderators, "we need to restore the integrity of the presidency.”

He added, “My job is to go out and make the case why he doesn't deserve to be President of the United States for another four years."

Sen. Elizabeth Warren (D-MA) speaks as South Bend, Indiana Mayor Pete Buttigieg (L) and former Vice President Joe Biden listen during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Justin Sullivan/Getty Images

Massachusetts Sen. Elizabeth Warren pivoted to a key pillar of her platform: her anti-corruption bill, arguing, “That vote will play out over the next several weeks. But the way I see this is, we've now seen the impact of corruption."

She added, "That's what's clearly on the stage in 2020, is how we are going to run against the most corrupt president in living history.”

South Bend, Indiana Mayor Pete Buttigieg, pushed beyond the divisive partisanship consuming Washington amid the ongoing impeachment fight, striking an optimistic tone as he pitched his campaign as one of changing the course of the country.

“At the end of the day, this is beyond public opinion. This is beyond polls. This is beyond politics. The president left the House with no choice,” he asserted, saying this is what the election is all about. “No matter what happens in the Senate, it is up to us in 2020. This is our chance to refuse to be taken in by the helplessness, to refuse and reject the cynicism."

South Bend, Indiana Mayor Pete Buttigieg speaks as Sen. Elizabeth Warren (D-MA) listens during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Justin Sullivan/Getty Images

‘Wine caves’ and ‘purity tests’ bring feuds to the forefront

The Democratic detente that largely defined the last debate ended in the second hour of sparring in Los Angeles.

Several feuds that have been bubbling on the campaign trail in recent weeks finally boiled over on the debate stage Thursday night.

After weeks of publicly trading words on the trail, Buttigieg and Warren stood shoulder-to-shoulder in one of the nights' most pitched fights over the role of big money donors in American politics.

“Billionaires in wine caves should not pick the next president of the United States. I do not sell access to my time,” Warren said in reference to a recent Buttigieg fundraising event in California that earned the candidate scorn from the progressives in the race.

“This is the problem with issuing purity tests you cannot yourself pass,” Buttigieg said in response, pointing out the fact that while she was running for the U.S. Senate, Warren followed the same path he did.

The clash was perhaps a preview of a rivalry between two candidates competing for a very similar set of voters as the first nominating contests draw near.

Democratic presidential candidate entrepreneur Andrew Yang speaks during a Democratic presidential primary debate Thursday, Dec. 19, 2019, in Los Angeles. Chris Carlson/AP Photo

The lack of diversity reverberated on and off stage

Entrepreneur Andrew Yang was the only candidate of color on stage, a fact he lamented during the only line of questioning that addressed the awkward fact.

“I miss Kamala, I miss Cory. Though I think Cory will be back,” Yang said in reference to Sen. Kamala Harris, who dropped out of the race earlier this month, and New Jersey Sen. Cory Booker, who did not qualify for the debate.

The exchange highlights the struggles that Booker, Harris and other candidates of color have had in garnering enough support to break through in what began as a historically crowded race.

Not to be outdone, Booker aired a national television ad during the debate, hoping that a final push will vault him back into competitive territory.

Democratic presidential candidate Sen. Amy Klobuchar speaks during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Justin Sullivan/Getty Images

The smallest stage gave way for a bigger impact from lower tier

From the onset of the matchup, the sixth debate was defined by being the smallest stage yet, and that fact allowed for those contenders on the wings of the stage -- often too far on the edges to be heard, including Minnesota Sen. Amy Klobuchar and Yang -- to amplify their voices and message to score a much-needed breakout moment.

With significantly more time than past debates, Yang stood out not only as the lone minority candidate on stage, but also as an unvarnished voice of a political outsider.

He kicked off his performance by saying, “we have to stop being obsessed over impeachment,” before later landing applause from the audience for arguing that both men and women leaders are needed in government.

"Because the fact is, if you get too many men alone and leave us alone for a while, we kind of become morons," he said.

Amy Klobuchar listens to Tom Steyer speak on stage during the sixth Democratic primary debate of the 2020 presidential campaign season co-hosted by PBS NewsHour & Politico at Loyola Marymount University in Los Angeles, California on December 19, 2019. Frederic J. Brown/AFP via Getty Images

Klobuchar, too, entered the night with even more urgency to tactically challenge her opponents, in the hopes of overtaking them in the polls.

The senator, returning to her clash with Buttigieg, took aim at one of his perceived vulnerabilities -- experience -- before touting her record of success as a campaigner in swing areas of the country.

“We should have someone heading up this ticket that has actually won and been able to show that they can gather the support that you talk about of moderate Republicans and independents, as well as a fired up democratic base,” Klobuchar said. “And not just done it once, I have done it three times. I think winning matters. I think a track record of getting things done matters.”

Democratic presidential hopeful former Vice President Joe Biden takes part in the sixth Democratic primary debate of the 2020 presidential campaign season co-hosted by PBS NewsHour & Politico at Loyola Marymount University in Los Angeles, California on December 19, 2019. Robyn Beck/AFP via Getty Images

Biden avoids the heat as he looks to solidify his lead

The former vice president came into Thursday night’s debate with a solidified lead in the national polls, and while he sparred with Sanders on healthcare and his vote on the Iraq War, he largely avoided the ire of his fellow candidates and pushed the central philosophy of his campaign.

“I refuse to accept the notion, as some on this stage do, that we can never, never get to a place where we have cooperation again,” Biden said, defending the idea of working with Republicans.

Sen. Bernie Sanders speaks as former Vice President Joe Biden listens during the Democratic presidential primary debate at Loyola Marymount University on December 19, 2019 in Los Angeles, California. Justin Sullivan/Getty Images

“If that's the case, we're dead as a country," he said.

While Buttigieg, who has steadily risen in the polls in Iowa, took shots from both Warren and Klobuchar, Biden did not see the same kind of sustained attacks he did in previous debates from the likes of Harris and Booker.

But don’t expect Biden to have an easy path in the final weeks leading up to Iowa, as multiple candidates are well-aware that the coalition the former vice president has assembled of both African-Americans and working class white voters will need to be chipped away if they want any chance at winning the nomination.