Amy Klobuchar (L): "It is easy to go after Washington because that's a popular thing to do. It is much harder to lead and much harder to take those difficult positions," Klobuchar said to rival Pete Buttigieg. "But what you said Pete as you were campaigning through Iowa as three of us were jurors in the impeachment hearing, you said it was exhausting to watch and that you wanted to turn the channel and watch cartoons."

REUTERS/Brian Snyder 

Pete Buttigieg, Elizabeth Warren, Joe Biden and Bernie Sanders all try to be heard. REUTERS/Brian Snyder 

Joe Biden on Bernie Sanders: "Bernie has labeled himself, not me, a democratic socialist. I think that's the label that the president is going to lay on everyone running with Bernie if he is the nominee."

REUTERS/Brian Snyder 

Pete Buttigieg defended Joe Biden when a moderator asked if the Republican investigation into his son, Hunter Biden, would be a liability if he was a nominee. "We've got to draw a line. ... To be the kind of human being who would seek to turn someone against his own son, who would seek to weaponize a son against his own father, is an unbelievably dishonorable thing. That is just one more example of why we as a party have to be completely united in doing whatever it takes, at the end of the day, to make sure that this president does not get a second term."

REUTERS/Brian Snyder 

Elizabeth Warren: "Election time, year after year, election after election after election, Democrats go to people in the black community and say: Boy we really care about these issues, racism is terrible. We all want to do something. And then, somehow, the problem just seems to keep getting worse. Well I think it's time we have real, concrete plans that are going to make a difference in people's lives."

REUTERS/Brian Snyder 

Bernie Sanders: "Everybody up here by the way is united; no matter who wins this damn thing, we're all going to stand together. I believe the way we beat Trump is by having the largest voter turnout in the history of his country."

REUTERS/Brian Snyder 

Amy Klobuchar: "We have a president that literally blames everyone in the world, and we have not talked about this enough. He blames Barack Obama for everything that goes wrong, he blames his Federal Reserve chair that he appointed himself. He blames the king of Denmark. Who does that? He blames the prime minister of Canada, for, he claims, cutting him out of the Canadian version of 'Home Alone 2.' Who does that? That's what Donald Trump does."

REUTERS/Brian Snyder 

Tom Steyer: "We're going to have to take Mr. Trump down on the economy. Because if you listen to him, he's crowing about it every single day, and he's going to beat us unless we can take him down on the economy, stupid. And that's the issue here is not about who has the best healthcare plan. All the healthcare plans are better, a million times better. The question is, who can go toe-to-toe with Mr. Trump, who can take down Mr. Trump, because he's the real threat to the country."

REUTERS/Brian Snyder 

Andrew Yang: "Donald Trump is not the cause of all our problems, and we're making a mistake when we act like he is. He is a symptom of a disease that has been building up in our communities for years and decades, and it is our job to get to the harder work of actually curing the disease."

REUTERS/Brian Snyder 

Bernie Sanders rejected criticism that his agenda is too radical to win the general election, saying he could bring people together by "presenting an agenda that works for the working people of this country, not the billionaire class ... The way you bring people together is by ending the international disgrace of this country being the only major nation on Earth not to guarantee healthcare to all people as a human right."

REUTERS/Brian Snyder 

When asked why she was better to lead the country than former New York City Mayor Michael Bloomberg, who did not participate in the debate, Elizabeth Warren said: "Look, I don't think anyone ought to be able to buy their way into a nomination or to be president of the United States. I don't think any billionaire ought to be able to do it, and I don't think people who suck up to billionaires in order to fund their campaigns ought to do it."

REUTERS/Brian Snyder 

Pete Buttigieg criticized Joe Biden for voting for the Iraq war in 2002 as a senator. "I believe that I have the judgment to help us get through these situations where obviously the vice president made the wrong decision when it came to such an important moment in our foreign policy. And looking forward, we've got to recognize just how much is going to be on the plate of the next president that is different in kind from what we have faced before."

REUTERS/Brian Snyder 

Joe Biden: "This is a long race. I took a hit in Iowa, and I'll probably take a hit here. Traditionally, Bernie won by 20 points last time, and usually it's the neighboring senators that do well. But no matter what, I'm still in this for the same reason. We have to restore the soul of this country, bring back the middle class, and make sure we bring people together."

REUTERS/Brian Snyder 

Referring to Bernie Sanders' Medicare for All proposal, Joe Biden said: "Imagine you're going unite the country, walking into Congress and saying, 'I got this bill. It's going provide healthcare for everybody. I don't know how much it's going cost. We'll figure it out later.' Who do you think is going to get that passed?"

REUTERS/Brian Snyder 

Joe Biden: "And Mayor (Pete) Buttigieg is a great guy and a real patriot. He's a mayor of a small city who has done some good things but has not demonstrated he has the ability to -- and we'll soon find out -- to get a broad scope of support across the spectrum, including African Americans and Latinos."

REUTERS/Brian Snyder 

Pete Buttigieg: "Now we have a president who says the economy is fantastic because the Dow Jones is looking good. And I'm sure if you've got a building with your name on it close to Wall Street, then that really is the same thing as the economy to you. But the problem is we've had an economy grow and not be able to lift up those in most need, or even so many in the middle."

REUTERS/Brian Snyder 

Young members of the audience listen during the debate. REUTERS/Brian Snyder 

Andrew Yang, Pete Buttigieg, Bernie Sanders, Joe Biden, Elizabeth Warren, Amy Klobuchar and Tom Steyer debate. REUTERS/Brendan Mcdermid 

Elizabeth Warren talks with Bernie Sanders as Amy Klobuchar looks on. REUTERS/Brian Snyder 

Pete Buttigieg and his husband Chasten shake hands with members of the audience at the conclusion. REUTERS/Brian Snyder 

Pete Buttigieg is seen on TV monitors in the media center. REUTERS/Brendan McDermid 

Pete Buttigieg, Bernie Sanders, Joe Biden and Elizabeth Warren (L-R) gather onstage. REUTERS/Brian Snyder 

Bernie Sanders talks with Elizabeth Warren during a break. REUTERS/Brian Snyder 

(L-R) Andrew Yang, Pete Buttigieg, Bernie Sanders, Joe Biden, Elizabeth Warren, Amy Klobuchar and Tom Steyer pose before the debate. REUTERS/Brian Snyder 

Moderators (R to L) ABC Chief Anchor George Stephanopoulos, ABC World News Tonight Anchor and Managing Editor David Muir and ABC News Live Anchor Linsey Davis speak to the audience before the debate. REUTERS/Brian Snyder 

Democratic National Committee Chairman Tom Perez speaks to the crowd before the debate. REUTERS/Brian Snyder