The theme of Wednesday night's race was, in particular and constantly, in focus.
At one point, Booker and Kamala Harris – both African-American senators – warned of a lack of African-American support for Buttigieg. Biden later boasted of his black supporters, but erroneously suggested that Harris was not an African-American senator.
While this was not the first debate in which race played a major role, Wednesday marked the first time President Trump was so heavily in the forefront.
This was the first hearing since the House launched an impeachment investigation into pressure on Ukraine to open a probe into Biden and his son, who were doing business in the country at the same time his father was involved in US politics there. And just an hour before the debate, the one-day impeachment hearing has just ended, ensuring that it will be a top topic for everyone's mind.
Here are some key moments from Wednesday's debate.
Harris, Booker warn against Butigieg as nominee
Black candidates on the stage have warned Democrats that they cannot afford to nominate a candidate who does not appeal to various constituencies.
Harris was careful not to attack Buttigieg personally because of his lack of appeal to black voters, but spoke of the "bigger problem".
"The bigger problem is that for too long, I think the candidates have taken the Democratic constituencies who were the backbone of the Democratic Party for cash and neglected these polling stations," Harris said.
She criticized the habit of candidates generally appearing in black communities shortly before the election but absent in most of their campaigns. The "question," she insisted, "must be where you are and what you will do. And do you understand what the people want? “
Buttigig, for his part, said he "completely" agreed with the criticism of Harris, who ended with the California senator, saying Democrats should recreate the Obama coalition to win.
"I welcome the challenge of connecting with black voters in America who still don't know me," Buttigig added. "Although I have no experience of ever being discriminated against because of the color of my skin, I have the experience of sometimes feeling like a stranger in my own country, turning the news around and seeing my rights come up for debate."
Giving a chance to respond, Harris said justice was being voted on in 2020, but again refused to directly criticize Butigieg. "The question is not really what the fight is. The problem should be how we win, "she said, calling on the Obama coalition again. "I keep referring to it because it's the last time we won. And the way these elections looked and what that coalition looked like was to have a leader who worked in many communities, knows those communities and has the opportunity to bring people together. "
Senator Corey Corricker was later asked a question about the southern border. But he took this opportunity to revive the discussion of race.
"I want to get back to the question of black voters. I have a lifetime of experience with black voters, "Booker said. “I was one of 18 years old. No one at this stage needs to have a focus group to hear from African-American voters, "said Butigieg's campaign curtain shot.
"Black voters are waking up and they are worried," Booker continued. "They were annoyed because the only time it seems that our questions are being paid to politicians is when people ask for their votes. And they're worried because the Democratic Party, we don't want to see people miss this opportunity and lose because we nominate someone they don't trust, they don't have authentic relationships. “
Biden is overwhelming in support of black voters
Biden and his campaign are understandably boasting about how he enjoys the strongest support of any African-American voter in any race, including two black senators fighting him, Harris and Booker.
But Biden could not leave well enough and exaggerate what he considered among his supporters to be "the only African American ever elected to the United States Senate."
"No," Booker said.
"That's not true," Harris said, speaking from experience because she is, in fact, an African-American elected to the US Senate, which does not support Biden. "The other is here," Harris laughed as the crowd laughed at her.
Then Biden tried to clear his remarks falsely by claiming: "I said – the first African American woman," the first African American woman.
The awkward exchange came just moments before Booker humorously summoned Biden for his recent remarks on the legalization of marijuana, though Booker had mistaken his facts as Biden said he opposed.
"I heard him literally say this week that I don't think we should legalize marijuana. I thought you might have been tall when you said that, "Booker said.
However, Biden said he believes marijuana should be decriminalized.
"I think we should decriminalize marijuana, period, and everyone who has a record should be jailed, their record deleted, to be complete," said Biden, who said he would not legalize it at the federal level and who he believes it can still be a "gateway drug".
Butigig, Gabbard boasts national security credentials
Buttigig said that "the Washington experience is not the only experience that matters", casting his military service in Afghanistan as an example of the type of experience a candidate for democracy should have.
But Hawaii's representative, Tulsi Gabbard, disagreed with the idea that their military service qualified them as chief commanders. Gabbard said he had "years of experience" serving in Congress for seven years, including on the committees on armed services, foreign affairs and home security.
"I think the latest example of your inexperience in national security and foreign policy stems from your recent reckless statement about how you as president would be ready to send our troops to Mexico to fight the cartels," she said.
"I know it is important for the Washington course to make remarks out of context, but it is amazing even by today's policy standards," Buttigig retorted.
He clarified that he was talking about US-Mexico co-operation. "Do you seriously think anyone on this scene is proposing to attack Mexico?" He asked.
“I'm talking about building alliances. And if your question is about experience, let's talk about assessment, too, "he said. "One of the foreign leaders you mentioned was Bashar al-Assad. I have in my experience as it is, whether you consider it important or not, because it was not accumulated in Washington, a sufficient judgment that I would not sit with a murderous dictator like that. "
Biden is dragging himself into Steyer's climate
California billionaire Tom Stayer has been one of the loudest advocates – and biggest consumers – of climate change and is the only candidate in the race to say he will declare a national emergency and use the executive to drastically scale fossil fuels.
"I am the only person at this stage who will say that climate is the number one priority for me. Vice President Biden would not say so. Senator Warren is not going to say that, "Stayer said. "It's a state of emergency and I would declare a state of emergency on the first day."
Biden, after being checked by name, got a chance to respond and was unexpectedly critical of how Stayer earned his money.
"While I succeeded in investing $ 900 billion in a renewal plan to invest more money in clean energy infrastructure than ever before," said Biden, "my friend was introducing more coal mines and producing more coal around the world, according to press, than produces the whole of the UK. Now, I welcome him back into the landscape here, and he's been there a long time. “
Stayer decided not to fight, and instead took the time to reiterate the importance of the issue.
Gabbard v. Harris
The last time a Hawaii official, Tulsi Gabbard, crossed swords with Senator Kamala Harris, she recorded the senator's record as a California prosecutor and her position on marijuana.
On Wednesday, Harris got a chance to go back to Gubbard, who has since become a Republican-leaning voter hero for her decision to criticize Democratic presidential nominee Hillary Clinton and their party.
"It is a party," Gabbard told the Democrats, "it is and continues to be influenced by the establishment of foreign policy in Washington represented by Hillary Clinton and others." Gabbard said Americans "seek to end this Bush-Clinton one." – Trump's foreign policy doctrine on regime change wars, overthrowing dictators in other countries. “
Harris, given the chance to gain weight, said "it is unfortunate that we have someone on this stage trying to be a Democratic candidate for US president, who spent four years on Fox News during the Obama administration criticizing him." President Obama ”
Harris also said that Gabbard "was hanging out [former Trump adviser] Steve Banon meets Donald Trump in the Tower of Trump, fails to call a war criminal as he is, a war criminal. And then he spends all his time in this campaign, again, criticizing the Democratic Party. "
Democrats respond to impeachment hearings
Wednesday's impeachment inquiry testimony by Ambassador Gordon Sundland, who has repeatedly confirmed that the Trump administration ultimately wants an investigation into Biden in return for military aid, was used as a starting point for Warren to speak out against corruption in the US political system. – and pull on your rivals.
"How did Ambassador Sundland get there?" Warren asked rhetorically. "You know, this is not a man who had qualifications except one. He wrote a check for a million dollars. And that tells us about what's happening in Washington, corruption. How money buys their way to Washington. You know, I ordered these months ago for the whole stance that donors think they will get ambassadors from the other side. "
Warren said she had pledged not to let that happen, but stressed that none of her colleagues were following her lead.
Unlike Warren, Senator Amy Klobuchar would not be required to vote to remove Trump's impeachment of the House and have a Senate hearing. Clobuchar made the distinction by saying Trump should be recalled, but she needed to hear all the facts first before deciding whether to remove her from office.
Senator Kamala Harris simply called Trump a "White House criminal," while Sanders addressed the issue.
"We just can't consume Donald Trump. Because if we are, you know what? We're losing the election, ”Sanders said, telling the suffering people without health insurance or a roof over their heads.
"What the American people can understand is that Congress can go and chew bubbles at the same time," Sanders said. "In other words, we can tackle Trump's corruption, but we must also advocate for the working families of this country."
"Lock it up!"
Trump's crowds started first: the chants "to lock" him on Hillary Clinton and then "to lock" him on Biden's son, Hunter Biden. But with six Trump aides and former campaign officials now convicted of crimes as he faces an impeachment probe, the Democrats at Sanders' rallies have begun chanting Trump, "lock him up."
Should Democrats Do It?
Asked if he was okay with it, Sanders didn't really answer the question.
"I think the people of this country are getting to the extent that this president thinks he is above the law. And, as the American people say, no one is above the law. And I think what the American people are saying is, in fact, that if this president broke the law, he should be tried like any other individual who breaks the law. "
For his part, Biden said he "will not direct the justice ministry, as this president does. I would allow them to make an independent judgment. I would not dictate who should be prosecuted or who should be persecuted. That is not the role of the President of the United States. It's the United States Attorney General, not the president's lawyer … the private lawyer. "
However, Biden said: "I think it's not a good idea to model after Trump and say, 'he concluded. "Behold, we must gather this land. Let's talk to people politely. "Then Biden briefly lost his speech on the need for citizenship and the importance of restoring the 'soul of this country' before returning to the concept that the Ministry of Justice should be independent.
Saunders said: "I think iso is right."
Clowner, master of the joke
Senator Amy Klobuchar drew contrasts with billionaire Tom Steyer and the rising Boutigyeg using humor. "While I appreciate his work," she told Stier, "I'm someone who doesn't come from money. I see my husband there. In my first race in the Senate, I literally summoned everyone I knew and set what is still a record in the Senate for all time: I raised $ 17,000 from former guys. And I would like to point out: it is not a basis for enlargement. "
The crowd in the debate – and even some candidates on stage – burst into laughter.
Moments later, she clarified comments she had previously made in the campaign trail about Buttieg's slim biography. Klubuchar suggested a woman with her experience not be at this stage of the debate, but clarified on Wednesday that Butigige was qualified and "honored" to stand up to him.
"But what I said is true," she continued. "Women are held to a higher standard. Otherwise, we could play a game called "Name Your Favorite Woman President," which we couldn't do because they were all men. "
She ended her response with another well-received ginger: "If you think a woman can't beat Donald Trump, Nancy Pelosi does it every day."
Harris, Young are affecting Trump's foreign policy
Democrats have attacked Trump's foreign policy record. In Harris' words, "Donald Trump got punk" by North Korean leader Kim Jong Un, who provided a photo op at a Trump summit in Singapore last year.
Harris said Trump's foreign policy was "born of a very fragile ego". Citing Trump's decision to withdraw from the Paris climate deal and the Iranian nuclear deal and remove US troops from Syria, Harris labeled Trump "the greatest threat to our nation's national security".
Moments later, asked what he would say to Russian President Vladimir Putin in the first call if he becomes president, businessman Andrew Young needed a few moments to ponder. "Well, first, I'll say 'Alas I beat your boyfriend,'" he said after a long pause. "Or I'm not sorry."
Trump is seeking a friendly relationship with Putin, though the US intelligence community has said Moscow was meddling in the 2016 election to bolster Trump over Democrat Hillary Clinton.
"And second," Yang added, "I would say that the days of meddling in the US election are over and we will take any undermining of our democratic processes as an act of hostility and aggression."
Bido Biden controls his power
Biden used his first response, arguing that the Democratic nominee would need to be able to defeat Trump next fall and go to states like Georgia and North Carolina to help the Democrats regain control of the Senate.
"This is what I'm going to do," Biden said. "You have to ask yourself here who is likely to win the nomination first – to win the presidency first. And second, which is likely to increase the number of Democrats in the House and Senate. "
He then turned to impeachment, insisting he learned during a House Democrats hearing that Trump did not want him nominated. "That's pretty clear," he said. "He provided help to make sure that, at the same time, innocent people … were killing Russian soldiers."
Biden added that he also learned that Russian President Vladimir Putin does not want him to be president. „Па научив многу за овие расправи рано од овие расправи што се одржуваат“, рече тој, пред да се затвори со сугестијата дека тој е единствениот кандидат кој може да им помогне на демократите да ја задржат контролата врз Домот, да го освојат Сенатот и го избрка Трамп од Белата куќа.