The Democratic debate included the introduction of some of the candidates to a national audience, fiery exchanges and some tough questions.
Here are some of the best lines from tonight's debate:
"...the American people are sick and tired of hearing about your damn e-mails." -- Bernie Sanders on the Hillary Clinton email controversy.
It was inevitable that Clinton would get a question about her private email server.
Clinton answered the question but insisted that she didn't want to talk about her emails.
That's when Sanders chimed in: "Let me say something that may not be great politics, but I think the secretary is right. And that is that the American people are sick and tired of hearing about your damn e-mails."
Sanders' comments got applause from the audience and Clinton thanked him with a handshake.
CNN debate moderator Anderson Cooper provided Clinton a window of opportunity to respond, and Clinton kept it brief.
"Secretary Clinton, do you want to respond?" Cooper asked.
"No," Clinton said.
"Donald Trump, that carnival barker in the Republican party" -- Martin O'Malley on Donald Trump
The night would not be complete without an attack on the GOP front-runner.
"And a lot of the xenophobes, like some that we've heard, like Donald Trump, that carnival barker in the Republican party tried to mischaracterize it as free tuition for illegal immigrants," O'Malley said during his argument that he would grant undocumented immigrants in-state tuition.
"I have had no scandals." -- Lincoln Chafee
While introducing himself, Chafee pitched himself to voters as a candidate who hasn't faced a scandal.
"I'm very proud that over my almost 30 years of public service I have had no scandals. I've always been honest," Chafee said. "Had the courage to take the long-term view and I've shown good judgment. I have high ethical standards."
"You're looking at a block of granite." -- Chafee on his changing of parties
Chafee has changed parties from Republican to Independent and finally to Democrat. Cooper asked Chafee why should liberal voters trust he won't change parties again.
Chafee insisted his stances on the issues have been solid.
"Anderson, you're looking at a block of granite when it comes to the issues," Chafee said. The former Rhode Island governor went on to say that he is a "proud Democrat" and has not changed on the issues.
"We are not Denmark." -- Clinton responds to Sanders' comment
Sanders was making the argument that the U.S. should look at Denmark, Sweden and Norway to "learn from what they have accomplished for their working people."
"I think what Senator Sanders is saying certainly makes sense in the terms of the inequality that we have," Clinton said. "But we are not Denmark. I love Denmark."
"No not at all." -- Clinton on Sanders' gun position
The first strong attack from one candidate against another on stage came from Clinton against Sanders. Cooper asked Clinton if she thought Sanders was strong on guns. Clinton quickly answered, "No, not at all."
Sanders responded, "What I can tell Secretary Clinton that all the shouting in the world is not going to do what I would hope all of us want. And that is keep guns out of the hands of people who should not have those guns and end this horrible violence that we are seeing."
"It was my very first vote..." Chafee on defending his record on dealing with Wall Street.
Chafee did not give a direct answer to the question of whether he knew he was voting for repealing the Glass-Steagall Act when he first became a U.S. senator back in 1999.
"I had just arrived in the Senate," Chafee said.
Cooper prompted: "Are you saying you didn't know what you were voting for?"
"It was my very first vote and it was 92-5," Chafee said before getting cut off.
"With all due respect, what does that say about you that you're casting a vote that you didn't know what you were voting for?" Cooper asked of Chafee.
"I think you're being a little rough, I had just arrived in the United States Senate, I had been Mayor of my city, my dad had died I had been appointed by the governor, It was the first vote..." Chafee answered.
"This hasn't been equal time." -- Jim Webb
Webb, certainly one of the lesser-known candidates on stage, seemingly got upset when he felt he wasn't getting enough speaking time.
"I know my time has run out but in speaking of changing positions and the position on how this debate has occurred is kind of frustrating because unless somebody mentions my name I can't get into the discussion," Webb said.
Cooper fought back, "You agreed to the rules and you're wasting time."
Webb went on to add: "This hasn't been equal time."