Some 20 presidential primary contenders return to a pair of stages on Tuesday and Wednesday seeking a breakout moment at the second Democratic debates.

For the lower-polling candidates in the field, Detroit likely will be their last chance to impress a national audience. Here is how the night unfolded.

10:40 p.m.: The debate has ended

The debate has ended with Warren and Sanders wrapping up.

Sen. Elizabeth Warren said, " I will not only beat Donald Trump in 2020, I'll start to make real change come 2021."

Sen. Bernie Sanders said, "I'm running for president not just to defeat the most dangerous president in the history of the country. A racist and a sexist. And a homophobe. I'm running to transform this country and to stand with the working class of America."

10:40 p.m.: The middle of the pack closes out the second debates with messages of hope

Former Texas Rep. Beto O'Rourke: "We are as divided in polarized as a country as we have ever been. Right now, we have a president who uses fear to try to drive us further apart. To meet this challenge, we have to have hope in one another and faith in a future of the country that includes everyone."

10:33 p.m.: Closing statements get underway, zeroing in on Trump

Montana Gov. Steve Bullock, the first Democrat to deliver his closing remarks, said: "I'm running for president to beat Donald Trump. Win back the places we lost. And make sure that Americans know that where Washington left them behind in the economy and political system, I'll be there."

Author Marianne Williamson asserted: "Our problem is not just that we need to defeat Trump. We need a plan to solve institutionalized hatred and white nationalism. In order to do that we need more than intellectual argument. We need radical truth-telling. Not just to talk about health care but why we're so sick all the time...The only way to fight -- you can't fight dog whistles. You have to override them with new voices."

Former Maryland Rep. John Delaney said: "Donald Trump is the symptom of the disease. And the disease is divisiveness. I'm the only one on stage talking about cures that disease...We can do it with real solutions, not impossible promises."

Rep. Tim Ryan said, "There's not going to be a savior. Not going to be a super-star. That will fix all this. It's going to be you and me. It's going to be us. That's how we fix this country. You and I coming together to do big things. To imagine the new country that we want by coming together. Not left or right. New and better."

Former Colorado Governor John Hickenlooper said, " I have done the things that most of the people on this stage are talking about. And I know I can get results. I can lead the people of this country towards a stronger, a healthier, and a more secure future. And defeat Donald Trump and return this country to its glory."

Sen. Amy Klobuchar said, " I will govern will integrity. We have a president where people turn off the TV when they see him. Not me. I will make you proud as your president."

10:22 p.m. The youngest and oldest Democratic candidates address whether age matters when vying for the presidency

The youngest candidate in the race, Mayor Pete Buttigieg, standing next to the oldest candidate Sen. Bernie Sanders said, " I don't care how old you are. I care about your vision. I think it matters we have a new generation of leaders stepping up around the world."

Sanders added, "Pete is right. It's a question of vision. Whether you are young or old or in between."

10:20 p.m. ABC News political commentator Cokie Roberts: "how Democrats appeal to their own voters and still attract the majority in the general election"

After the first debate, Democrats learned that many of the ideas they championed weren't popular with the majority of voters. So in tonight's contest, the more moderate candidates tried to paint the front-runners on the stage--Sanders and Warren--as pie in the sky dreamers with their plans for free college and a completely revamped healthcare system. Both fought back with familiar arguments against big corporations and big money. It started to sound awfully tired by the end, though still popular with most Democrats. The problem not solved tonight: how Democrats appeal to their own voters and still attract the majority in the general election. No one managed to breakthrough. Now it's Joe Biden's turn to try to make the case for moderation with an entire stage full of candidates likely to try to keep him from succeeding.

10:20 p.m. Sen. Elizabeth Warren said that she will never use nuclear weapons first

"The United States is not going to use nuclear weapons preemptively," Warren said. "We need to say so to the entire world. It reduces the likelihood someone miscalculates or misunderstands. Our first responsibility is to keep ourselves safe. And what's happening right now with Donald Trump is they keep expanding the different ways we have nuclear weapons. The different ways they can be used puts us all at risk."

10:19 p.m. Beto O'Rourke said he will not start new wars as president

"There's no reason for us to be at war all over the world tonight," O'Rourke said. "As president, I will end the wars and we will not start new wars. We'll not send more members over seas to sacrifice lives and take the lives of others in our name. We can resolve the challenges peacefully," O'Rourke said

10:18 p.m.: Former U.S. Navy intelligence officer Pete Buttigieg invokes his military experience when discussing Afghanistan

Around the world, we will do whatever it takes to keep America safe. I thought I was one of the last troops leaving Afghanistan," the South Bend, Indiana mayor began. "Every time I see news about somebody being killed in Afghanistan I think about what it was like to hear an explosion and wonder whether it was somebody I knew or served with. Friend or roommate. Colleague. We're close to the day when we will wake up to the news of a casualty in Afghanistan who was not born on 9/11."

"I was sent into the war by a congressional authorization as well as a president. We need to talk not only about the need for a president committed to ending endless war. The fact that Congress has been asleep at the switch. And on my watch, I will propose that any authorization for the use of military force have a three-year sunset. And have to be renewed. If men and women in the military have the courage to serve, members of Congress have the courage to vote," he said to applause from the debate crowd inside the Fox Theatre.

10:15 p.m. Candidates tackle the threat of North Korea

Rep. Tim Ryan said that Sen. Amy Klobuchar is wrong for saying she would be open to meeting with North Korean dictator Kim Jong-Un.

"I love Amy Klobuchar but she's wrong on this one," Ryan said. "I don't think presidents of the United States meet with dictators."

Klobuchar said that she thinks the two lawmakers agree, but that she believes you should always be open to the possibility to meet with "anyone at any place."

"I do believe you meet with people but better have an agenda and put our interests of our country first," Klobuchar said.

10:11 p.m.: Bernie Sanders talks his approach to foreign policy

When asked about voters hearing a similar message from him and President Trump on foreign policy, Sen. Bernie Sanders, I-Vt., responded, "Trump is a pathological liar. I tell the truth. We have been in a Afghanistan I think 18 years. In Iraq 16 or 17 years. We have spent $5 trillion on the wall. On terror. And probably more terrorists out there now than before it began. We're going to spend the Congress passed I will not vote for, a $715 billion military budget more than the ten next countries combined. What we need is a foreign policy that focuses on diplomacy and ending conflicts by people sitting at a table."

10:06 p.m. Student loan debt forgiveness gets its moment from 2020 candidates

"If we want to start wiping away student debt here's where I start. I would start with the for-profit colleges that took advantage of people. Especially veterans," Mayor Pete Buttigieg said.

Marianne Williamson defended her views that everyone, including children from wealthier families, should get free college education.

"I think all domestic and international policy should be based on the idea that anything we do to help people thrive is stimulation to our economy. That's how you stimulate the economy. So if a few people take advantage of four or five people who were going to take the money they have in the bank, when you look at this $1.5 trillion college debt."

She criticized, to loud applause, her opponents saying, "I wonder why you're Democrats. You think there's something wrong about using the instruments of government to help people. That is what government should do. It should all policies should help people thrive. That is how we'll have peace and prosperity."

10:04 p.m. John Delaney says he should pay higher taxes due to his wealth

"I think wealthy Americans have to pay more," Delaney said. "I grew up in a blue-collar family. First in the family to go to college. A successful entrepreneur. Created thousands of jobs. Supported thousands of entrepreneurs around the country. And I have done well financially. I should pay more in tax. Wealthy Americans should pay more"

10:03 p.m.: Pete Buttigieg continues to reclaim the religious mantle from GOP

Mayor Pete Buttigieg, when responding to a question on General Motors plant closures in Michigan, said, "This is so much bigger than a trade fight. This is about a moment when the economy is changing before our eyes. There are people in the economy who go through more jobs in a week than my parents went through in the lifetime. It's where I proposed we allow gig workers to unionize."

He then invoked the Bible, when attacking Republicans on not passing a bill on the minimum wage: "The minimum wage is too low. So-called conservative Christian senators right now in the Senate are blocking a bill to raise the minimum wage. When scripture says whoever oppresses the poor taunts their maker."

10:01 p.m. Gov. Steve Bullock takes aim at President Donald Trump's tweets

"Every time the Trump tweets we lose hundreds of thousands of dollars. If Montana had to eat all the wheat we produce, they'd have to eat 40 loaves of bread a day," Bullock said.

10:00 p.m.: John Delaney again goes after Elizabeth Warren, this time on trade

"This is what I don't understand," Former Maryland Congressman John Delaney said. "President Trump wants to build physical walls and beat up on immigrants. Most of the folks running for president want to build economic walls to free trade."

But Sen. Elizabeth Warren, D-Mass., responded, "For decades we have had a trade policy that has been written by giant multinational corporations to help giant multinational corporations."

After former Texas Congressman Beto O'Rourke weighed in, saying, "When have we ever gone to war including a trade war without allies and friends and partners as president we will hold China accountable and bring allies and friends like the European union to bare. And negotiate trade deals that favor farmers and American workers and protect human rights and the environment and labor. Not just here in the United States."

Vermont Sen. Bernie Sanders, I-Vt., then came to Warren's defense, adding, "Look I believe I'm the only member of Congress who not only voted against the disaster trade agreements with China, which cost over 4 million jobs, but also helped lead the effort against the agreements. Elizabeth is right. If anybody here thinks that corporate America gives one damn about the average American worker, you're mistaken."

Warren later chimed in, "Anyone who thinks the trade deals are about tariffs doesn't understand what's going

9:52 p.m. Rep. Tim Ryan sides with President Trump on trade

"I think President Trump was onto something when he talked about China," Ryan said. "China has been abusing the economic system for a long time. They steal intellectual property. They subsidize goods. They eroded manufacturing. We transfer our wealth of the middle class either up to the top 1% or to China for them to build the military. So I think we need some targeted response against China. You out-compete them. That's why I put a chief manufacturing officer in place to make sure we rebuild the manufacturing base."

He said he would have to re-evaluate if he would continue Trump's steel tariffs before attacking the president on the execution of his agenda, "He's bungled the whole thing. Here's the problem with President Trump. He has a tactical move what's the grand strategy for the United States."

9:47 p.m.: Marianne Williamson details her stance on reparations

After Texas Congressman Beto O'Rourke said he would sign into law Rep. Sheila Jackson Lee's reparations bill, Marianne Williamson responded, "I appreciate what Congressman O'Rourke has said."

But she added, "It's not $500 billion in financial assistance. It's $500 billion, 200 to $500 billion payment of a debt that is owed. That is what reparations is ... We need to recognize when it comes to the economic gap between blacks and whites in America, it does come from a great injustice that has never been dealt with."

"This is part of the dark underbelly of American society, the rainfall, the bigotry, and the entire conversation that we're having here tonight, if you think any of this wonkiness is going to deal with this dark psychic force of the collectivized hatred that this president is bringing up in this country, then I'm afraid that the Democrats are going to see some very dark days."

Her response was met by loud applause.

9:45 p.m. Beto O'Rourke spotlights the legacy of slavery in the country

"I want to acknowledge something that we're all touching on which is the very foundation of this country, the wealth that we have built, the way we became the greatest country on the face of the planet was literally on the backs of those who were kidnapped and brought here by force," O'Rourke said. "The legacy of slavery and segregation and Jim Crow and suppression is alive and well in every aspect of the economy and country."

9:44 p.m.: Amy Klobuchar takes on Trump's economic agenda and his bigotry

The Minnesota Senator was asked about how she would appeal to Trump voters who prioritize the economy over his bigotry, to which she replied:

"There are people that voted for Donald Trump before that aren't racist, they wanted a better shake in the economy and so I would appeal to them. But I don't think anyone can justify what this president is doing," before adding, "Little kids literally woke up this weekend, turned on the TV and saw their president calling their city the town of Baltimore nothing more than a home for rats. And I can tell you as your president, that will stop."

9:43 p.m. Mayor Pete Buttigieg defends his record dealing with race in South Bend, Indiana

"As an urban mayor serving a diverse community, the racial divide lives within me," Buttigieg said. "I'm not saying that I became mayor and racism or crime or poverty ended on my watch. But in our city, we have come together repeatedly to tackle challenges like the fact that far too many people were not getting the help they needed in their housing and so we directed it to a historically underinvested African-American neighborhood."

9:40 p.m.: Elizabeth Warren calls Gilroy shooting 'domestic terrorism'

When asked a question about the rise of white supremacy after the shooting in Gilroy, California, Sen. Elizabeth Warren, D-Mass., said, "Call it out for what it is, domestic terrorism. We live in a country where the president is advancing environmental racism, criminal justice racism, economic racism, health care racism, the way we do better is to fight back and show something better."

"I have a plan," she added.

9:38 p.m. Race takes center-stage at the debate

Former Texas Congressman Beto O'Rourke made his case for why he is the best candidate to heal the racial divide in America.

"We'll call his racism out for what it is, and also talk about its consequences. It doesn't just offend our sensibilities to hear him say send her back about a member of Congress because she's a woman of color, because she's a Muslim American, doesn't just offend our sensibilities when he calls Mexican immigrants, rapists or criminals and seeks to ban all Muslims from the shores of a country that is comprised of people from the world over, from every tradition of faith," O'Rourke said.

Hickenlooper weighed in saying, "The core value behind this entire country's history is working towards a more perfect union, that all people are created equal, and we have fallen far away from that."

"In Colorado, when I was mayor, we got to universal pre-k for every kid in the urban city. We did major police reform, ten years before Ferguson, why is it now that five years after Ferguson, we don't have anything. How did we get affordable housing, we created a scholarship fund for every kid. You have to deliver a vision like that for the whole country," Hickenlooper added.

9:37 p.m.: Flint water crisis gets its moment at debate

Sen. Amy Klobuchar, D-Minn., the first candidate to field a question on infrastructure, immediately brought up the Flint water crisis, saying, "I was just in Flint, and they are still drinking bottled water in that town, and that is outrageous, and my plan, and I am the first one that came out with an infrastructure plan and I did that because this is a bread and butter issue for people that are caught in traffic jams."

"I truly believe that if we're going to move on infrastructure in climate change, you need a voice from the heartland," she said.

9:33 p.m.: Bernie Sanders defends his progressive agenda on climate change

Under attack from moderate candidate, Ohio Congressman Tim Ryan and Montana Gov. Steve Bullock, Vermont Sen. Bernie Sanders continues to focus his ire on Republicans and the fossil fuel industry.

"I get a little bit tired of Democrats afraid of big ideas," Sanders began. "Republicans are not afraid of big ideas. They could give a trillion dollars in tax breaks to billionaires and profitable corporations."

He later added, "On this issue, my friends, there is no choice, we have got to be super aggressive if we love our children and if we want to leave them a planet that is healthy and is habitable. So I don't disagree with Tim. What that means is we got to a, take on the fossil fuel industry."

He also said: "Ain't nobody in the Congress is more strongly pro-worker than I am. So when I talk about taking on the fossil fuel industry, what I am also talking about is a just transition."

9:27 p.m. Green New Deal under attack

After former U.S. Rep. John Delaney criticizes the progressive Green New Deal, former Governor John Hickenlooper also vocalizes his concern.

"I think the guarantee for a public job for everyone who wants one is a classic part of the problem. It's a distraction. I share the urgency of everyone up here. We have to recognize, I mean, everyone's got good ideas, what we do in this country is no matter than just a best practice. Right, it's what we do here is a best practice and a template but it's got to be done all over the world," Hickenlooper said.

Sen. Elizabeth Warren comes to the defense of the Green New Deal saying, "Look, I put a real policy on the table to create 1.2 million new jobs in green manufacturing. There's going to be a $23 trillion worldwide market for this. This could revitalize huge cities across this country, and no one wants to talk about it. What you want to do is find the Republican talking point of a made-up piece of some other part and say, oh, we don't really have to do anything. That's the problem we've got in Washington right now. It continues to be a Washington that works great for oil companies, just not for people worried about climate change."

9:25 p.m. Climate change gets its moment in the debate

Former U.S. Rep. John Delaney takes the first question and tackles why he believes the Green New Deal is not realistic.

"First of all, because it ties its progress to other things that are completely unrelated to climate like universal health care, guaranteed government jobs and universal basic income. My plan gets us to net-zero by 2050 which we absolutely have to do for our kids and grandkids will get us there. I put a price on carbon, take all the money, give it back to the American people in a dividend. That was introduced on a bipartisan basis. It's the only significant bipartisan climate bill in the congress," Delaney said.

9:23 p.m.: Beto O'Rourke highlights his bipartisanship with President Trump

"I think a big part of leadership and showing our commitment to the American people is delivering on our commitments," former Texas Congressman Beto O'Rourke began. "As a member of Congress, when I learned that the El Paso VA had the worst wait times for mental health care in the country, meaning that care delayed functionally became care denied and was related to the suicide epidemic, we made it our priority and we turned around."

"We got it signed into law by the one person with whom I agree on almost nothing, Donald Trump," he said.

9:21 p.m. Sen. Bernie Sanders tells voters his vision of how to beat President Donald Trump in 2020

"To win this election and to defeat Donald Trump, which by the way, in my view is not going to be easy, we need to have a campaign of energy and excitement and of vision. We need to bring millions of young people into the political process in a way that we have never seen by among other things, making public colleges and universities tuition-free and canceling student debt."

9:18 p.m.: Elizabeth Warren takes on electability question

As questions surround the massive field of candidates about their ability to beat Donald Trump in a general election, Sen. Elizabeth Warren, D-Mass., said, "I know how to fight and I know how to win. I took on giant banks and I beat them. I took on Wall Street, and CEOs, and their lobbyists and their lawyers and I beat them. I took on a popular Republican incumbent senator, and I beat him. I remember when people said Barack Obama couldn't get elected. Shoot, I remember when people said Donald Trump couldn't get elected. But here's where we are."

Former Maryland Congressman John Delaney responded, "I think Democrats win when we run on real solutions, not impossible promises."

Warren, taking aim at Delaney, then quipped, "I don't understand why anybody goes to all the trouble of running to the president of the United States to talk about what we really can't do and shouldn't fight for. I don't get it."

9: 16 p.m. Rep. Tim Ryan doesn't put much weight on the current polls

After Sen. Bernie Sanders touted his lead in polls in battleground states, Ryan responded saying, "I would just say Hillary Clinton was winning in the polls, too. To take a snapshot in the polls today and apply it 16 months from now, whenever it is, I don't think is accurate."

9:15 p.m.: John Hickenlooper and Bernie Sanders throw their hands up in the air amid tense exchange

Former Colorado Gov. John Hickenlooper said of Vermont Sen. Bernie Sanders, in the middle of the debate of their heated exchange, said, "I think if we're going to force Americans to make these radical changes, they're not going to go along. Throw your hands up, but you haven't --"

Sanders replied, "I will," as he threw his hands up.

"I can do it," Hickenlooper said in response, also throwing his hands up in the air.

9:11 p.m John Hickenlooper calls out Sen. Bernie Sanders on health care as the fight morphs into moderates vs. progressives

"I'm saying the policies of this notion that you're going to take private insurance away from 180 million American, who many of them don't want to give it, many of them do want to get rid of it, but some don't, many don't. The Green New Deal makes sure that every American's guaranteed a government job if they want, that is a disaster. You might as well FedEx the election to Donald Trump," Hickenlooper said.

9:10 p.m.: ABC News' Deputy Political Director MaryAlice Parks: Debate on health care winners? Trump, Bernie ... Delaney?

CNN spent the first portion of the debate tonight focused on health care, specifically teeing up the disagreements between those who favor Medicare for All and those who are not.

Republicans likely loved it. The discussion revealed large, fundamental divides in both policy and messaging strategy among the Democrats. They spent time telling each other they were wrong and debating Sanders' plan in tough-to-follow detail.

Sanders' benefited too -- as again -- they were all debating his plan. And frankly, Medicare for all is a cleaner bumper sticker than "Medicare for all - kinda-sorta-with tricky economics."

At one point Sanders told Tapper his very question about taking away private insurance and raising taxes was a Republican taxing point. A strong moment for him.

Still, Warren repeatedly came to Sanders' defense and while doubling-down on her support of his bill, she at times seemed better able to control the conversations than he did.

One more winner -- former Congressman Jon Delaney, who, while disagreeing with Sanders, made smart points about doctor reimbursement and hospital closure. He looked like someone disagreeing with Sanders who actually understood health care policy.

9:09 p.m.: Democratic debate night 1: Fact-checking the candidates on the issues

Here's ABC News' fact check of the first of two Democratic presidential debates in Detroit between Marianne Williamson, Rep. Tim Ryan, Sen. Amy Klobuchar, Mayor Pete Buttigieg, Sen. Bernie Sanders, Sen. Elizabeth Warren, former Rep. Beto O'Rourke, former Gov. John Hickenlooper, former Rep. John Delaney and Gov. Steve Bullock. (Please refresh the page for updates.)

9:02 p.m.: Steve Bullock invokes a personal story on gun violence

In the middle of sharing his stance on gun violence, Montana Gov. Steve Bullock said, "I'm a gun owner, I hunt, like far too many people in America, I have been personally impacted by gun violence. I had an 11-year-old nephew, Jeremy, shot and killed on a playground."

"We need to start looking at this as a public health issue, not a political issue. I agree with Senator Klobuchar. It is the NRA," he added.

9:01 p.m. Gun debate highlights age gap between 2020 competitors

A 37-year-old Mayor Pete Buttigieg, spotlighted the age difference between him and 59-year-old Sen. Amy Klobuchar when he responded, "This is the exact same conversation we have been having when I was in high school. I was a junior when the Columbine shooting happened. I am the first generation to see school shootings. We have produced a second generation. We dare not allow there to be a third. Something is broken."

8:59 p.m. Sen. Amy Klobuchar, D-Minn., takes on the National Rifle Association while taking a jab at President Donald Trump

"This isn't just about a system or it's not just about words. This is about the NRA," Klobuchar said. " I sat across from the president of the United States after Parkland because I have been a leader on these issues and have the will to close the boyfriend loophole, and I watched and wrote down when nine times he said he wanted universal background checks. The next day he goes and he meets with the NRA and he folds. As your president, I will not fold"

8:59 p.m.: Former Colorado Gov. John Hickenlooper touts his tenure as chief executive on gun violence

"When I went to the movie theater in Aurora in 2012 and saw that footage of what happened at that crime scene, I'll never forget it, and we decided, you know, that we were going to go out and take on the NRA, and we passed in a purple state, we passed universal background checks," he said of his experience with tackling the issue of gun violence in the country.

Mayor Pete Buttigieg takes the first question on how to end the epidemic of gun violence.

"What we're doing hasn't worked because we haven't had a system in Washington capable of delivering what the American people have told us they want. 90% of Republicans want universal background checks, not to mention the common-sense solutions like red flag laws that disarm domestic abusers and flag mental health risks and an end to assault weapons, things like what I carried overseas in uniform that have no business in American neighborhood in peacetime, let alone anywhere near a school," Buttigieg said.

8:54 p.m.: Steve Bullock offers a middle-ground approach to immigration, spars with Elizabeth Warren

Montana Gov. Steve Bullock, the red-state Democrat, attempted to present a different perspective on stage, saying, " I think this is part of the discussion that shows how often these debates are detached from people's lives. We got a hundred thousand people showing up at the border right now. If we decriminalize entry, if we give health care to everyone, we'll have multiples of that. Don't take my word. That was President Obama's homeland security secretary that said that."

After calling Sen. Elizabeth Warren's plan on immigration "unrealistic," Bullock added, "You are playing into Donald Trump's hands. The challenge isn't that it's a criminal of to cross the border. The challenge is that Donald Trump is president and using this to rip families apart."

8:51 p.m.: Moderate Amy Klobuchar weighs in on immigration

Sen. Amy Klobuchar, D-Minn., opined on the current debate on immigration, particularly illegal border crossings, telling the audience in Detroit, "I would say there is a will to change this in Congress. What's missing is the right person in the White House.

"I believe that immigrants don't diminish America, they are America and if you want to do something about border security, you, first of all, change the rules so then you pass the bill, and what the bill will do is it will greatly reduce the deficit and give us some money for border security," she added.

8:50 p.m. Sen. Elizabeth Warren and John Hickenlooper spar on decriminalizing illegal border crossings

"The point is not about criminalization. That has given Donald Trump the tool to break families apart," Warren said.

"The frustration with what's going on in Washington is they are kicking the ball back and forth. Secure the borders and make sure whatever law we have doesn't allow children to be snatched from parents and put in cages. How hard can that be? On two debate nights, we have 170 years of Washington experience. Somehow it seems like that should be fairly fixable," Hickenlooper responded.

"Well, and one way to fix it is to decriminalize. That's the whole point," Warren said.

8:48 p.m.: Beto O'Rourke defends his stance on decriminalizing border corssings

Former Texas Congressman Beto O'Rourke shared his view on decriminalizing illegal border crossings, saying, "In my administration, after we have waived citizenship fees for green card holders, more than 9 million of our fellow Americans, free Dreamers who many fear of deportation and stop criminally prosecuting families and children for seeking asylum and refuge and for-profit detention and so that no family has to make that 2,000 mile journey, then I expect that people who come here follow our laws and we reserve the right to criminally prosecute them."

Mayor Pete Buttigieg tackles his proposal to decriminalize the border.

"If fraud is involved, that's suitable for the criminal statute. If not, it should be handled under civil law," Buttigieg said.

8:44 p.m.: 2019 Bernie Sanders sounds like 2016 Bernie Sanders

Hearkening back to when he said in a 2016 debate against Hillary Clinton, "The American people are sick and tired about hearing about your damn emails," Sen. Bernie Sanders, I-Vt., said Tuesday night about his 'Medicare for all' bill, "I wrote the damn bill."

8:43 p.m. Tim Ryan makes appeal to union workers on healthcare while attacking Sens. Elizabeth Warren and Bernie Sanders

"Here we are in Detroit, home of the auto workers and have union friends here tonight. This plan being offered by Senator Warren and Sanders will tell the union members that give away wages in order to get good health care that they will lose their health care because Washington is going to come in and tell them they have a better plan," Ryan said.

8:39 p.m. John Delaney says other 2020 candidates don't understand the health care system

"'I'm the only one on the stage with experience in the health care business and with all due respect, I don't think my colleagues understand the business," Delaney said. "The public option is great but doesn't go far enough. It doesn't go far enough. I'm proposing universal health care where everyone gets health care as a basic human right for free, but they have choices."

8:37 p.m.: Bernie Sanders goes after moderator Jake Tapper

Amid a response on the debate over healthcare, Sen. Bernie Sanders, I-Vt., took aim at CNN moderator, Jake Tapper and then the network as a whole for the ads running during the debate's commercial breaks.

"What I am talking about and others up here are talking about is no deductibles and no co-payments and Jake, your question is a Republican talking point. At the end of the day and by the way, and by the way, by the way, the health care industry will be advertising tonight on this program," he said.

8:33 p.m.: Pete Buttigieg, Beto O'Rourke dive into their positions on healthcare

"We don't have to stand up here speculating about whether the public option will be better or Medicare For All environment will be better than corporate options. We'll put it to the test," Mayor Pete Buttigieg said.

"I think you can buy into it. That's the idea of Medicare For All that want to," Buttigieg added.

But former Congressman Beto O'Rourke said, "The middle class will not pay more in taxes to ensure that every American is guaranteed world-class health care. I think we're being offered a false choice. Some who want to improve the Affordable Care Act at the margins, others who want a Medicare For All program that will force people off of private insurance, I have a better path: Medicare for America."

8:31 p.m. Gov. Steve Bullock answers for why he doesn't support Medicare-for-All

"At the end of the day I won't support any plan that rips away quality health care from individuals," Bullock said. "This is an example of wishlist economics. It used to be Republicans that wanted to repeal and replace, now many Democrats do, as well. We can get there with the public option, negotiating drug prices."

8:29 p.m.: Elizabeth Warren comes to Bernie Sanders' defense

Amid the first contentious moment between Sen. Bernie Sanders, I-Vt., and former Congressman John Delaney, D-Md., Sen. Elizabeth Warren, D-Mass., stood by her progressive ally, defending him from the attack.

"We are the Democrats. We are not about trying to take away health care from anyone. That's what the Republicans are trying to do," she said in response to Delaney. "We should stop using Republican talking points in order to talk with each other about how to best provide that health care."

8:27 p.m. John Delaney creates the first spar of the night with Bernie Sanders on health care

"I'm right about this," Delaney said. "We can create a universal health care system to give everyone basic health care for free, and I have a proposal to do it, but we don't have to go around and be the party of subtraction and telling half the country with private health insurance their health insurance is illegal."

"The fact of the matter is, tens of millions of people lose their health insurance every single year when they change jobs or their employer changes that insurance," Sanders added. "If you want stability in the health care system, if you want a system which gives you freedom of choice with regard to doctor or hospital, which is a system which will not bankrupt you, the answer is to get rid of the profits of the drug companies."

8: 25 p.m. Sen. Bernie Sanders tackles the first question of the night on health care

"Right now we have a dysfunctional health care system," Sanders said. "87 million uninsured or underinsured, 500,000 Americans every year going bankrupt because of medical bills. 30,000 people dying while the health care industry makes tens of billions of dollars in profit."

8:23 p.m. More Democrats make their case

Minnesota Sen. Amy Klobuchar: "Let's get real ... I have bold ideas, but they are grounded in reality. And yes, I will make some simple promises. I can win this, I'm from the midwest and I've won every race, every place, every time and I will govern with integrity."

Former Texas Beto O'Rourke: "I'm running for president because I believe that America discovers it's greatness at its moments of greatest need."

8:19 p.m. Democrats make their case to voters in their opening statements

Author and spiritual teacher Marianne Williamson: "We the American people must rise up and do what we do best and create a new possibility, say no to what we don't want and yes to what we know can be true."

Former U.S. Rep. John Delaney: "Folks, we have a choice. We can go down the road that senator Sanders and senator Warren want to take us with bad policies like medicare for all, free everything, and impossible promises that will turn off independent voters and get trump reelected."

Rep. Tim Ryan, D-Ohio: "The political system is broken, too, because the entire conversation is about left or right, where are you at on the political system and I'm here to say this isn't about left or right. This is about new and better and it's not about reforming old systems. It's about building new systems and tonight, I will offer solutions that are bold, that are realistic, and that are a clean break from the past."

Former Colorado GovJohn Hickenlooper: "Last year Democrats flipped 40 Republican seats in the house and not one of those 40 Democrats supported the policies of our front runners at center stage ... we focused on was making sure we got people together to get things done."

8:14 p.m. Steve Bullock gives the first opening statement of the night highlighting his ability to work with Republicans across the aisle

"Look, I'm a pro-choice, pro-union, Democrat that won three elections in a red state, not by compromising our values but by getting stuff done," Bullock said. "That's how we win back the places we lost."

8:04 p.m.: The first 10 candidates step onto the stage

Tuesday night's lineup from left to right on stage includes:

Ohio Rep. Tim Ryan

Minnesota Sen. Amy Klobuchar

South Bend Mayor Pete Buttigieg

Vermont Sen. Bernie Sanders

Massachusetts Sen. Elizabeth Warren

Former Texas Rep. Beto O'Rourke

Former Colorado Gov. John Hickenlooper

Former Maryland Rep. John Delaney

Montana Gov. Steve Bullock

8 p.m.: The debate is underway

Night one of the second Democratic debates is getting underway.

7:47 p.m.: Moments from taking the stage, Bullock wins lawsuit against the Trump administration

Just as 2020 candidate and Montana Gov. Steve Bullock was getting ready to take the stage for his first debate, his team delivered news about a victory back home: the governor just won a year-long lawsuit against the Trump administration.

Bullock, whose presidential message centers on removing dark money from politics, sued the Internal Revenue Service a year ago over a rule President Donald Trump's administration overturned, which had previously required politically-active nonprofit groups to disclose to the IRS names of donors.

In Federal Court in Montana, Judge Brian Morris ruled on Tuesday evening that the rule would be reinstated.

According to the docket, the court “holds unlawful" the rule as adopted by the IRS and said the agency “must follow the proper notice-and-comment procedures pursuant to the APA it if seeks to adopt a similar rule.”

According to the previous law, donors who gave $5,000 or more in their tax returns would be disclosed to the IRS, although the IRS would redact the donor names when making those documents public. Such groups are commonly called “dark money” groups because they don't disclose their donors publicly unlike other politically active groups that disclose their donors to the FEC such as super PACs.

Bullock, who did not qualify for the first Democratic debate in June, will make his debut Tuesday night at the second Democratic debate in Detroit.

ABC News' Cheyenne Haslett reports from Detroit

7:44 p.m.: The Democratic debates night one: Fast facts

There will be over 136 years of political experience showcased the debate stage tonight.

3 United States Senators: Sens. Bernie Sanders, Elizabeth Warren, and Amy Klobuchar 3 United States Representatives: Current Rep. Tim Ryan, and former Reps. Beto O’Rourke and John Delaney 2 Governors: Current Gov. Steve Bullock and former Gov. John Hickenlooper 1 Mayor: Pete Buttigieg 1 Author: Marianne Williamson

Debate stage podium positions (left-right): Williamson, Ryan, Klobuchar, Buttigieg, Sanders, Warren, O’Rourke, Hickenlooper, Delaney, Bullock

What’s different about the group? Tuesday will be Gov. Bullock’s first time on a debate stage for the 2020 election.

Oldest candidate – Sanders (77 years old) Youngest candidate – Buttigieg (37 years old)

Most political experience – Sanders Least political experience – Williamson

ABC News' Kelsey Walsh reports from New York City, New York

7:19 p.m.: John Delaney plans to throw punches Tuesday night

Former Maryland Rep. John Delaney will take a shot at making a name for himself on stage tonight by hitting Sens. Bernie Sanders and Elizabeth Warren, candidates he thinks are running on "impossible promises."

"I plan on drawing sharp contrasts," Delaney said in a sit down at his hotel today. "As I like to say, they are running on what I like to call, ‘impossible promises.’ And I’m running on real solutions to the issues that matter to the American people. And so that’s a really important contrast to make and that’s what I’m gonna do tonight." 162442

Top of the list, Delaney said, is Sen. Bernie Sanders, I-Vt.

"Because everything is either for free, or he reimagines the healthcare industry in a way that is just based on kind of fairy tale economics," he said.

In a statement his campaign put out less than hour before the debate is set to begin, Delaney's national press secretary, Michael Starr Hopkins, said in a statement, "Sanders isn't even a Democrat and we shouldn't let lead our party down a path that will mean we lose to Donald Trump."

Sen. Elizabeth Warren, D-Mass., is also up there.

"In many ways, she’s outsourced her healthcare plan to Sen. Sanders. So I think you know she is basically pursuing the same playbook," he said.

-ABC News' Cheyenne Haslett reports from Detroit, Michigan

5:45 p.m.: Steve Bullock shares a moment with his son hours before debate

Montana Gov. Steve Bullock, who will be making his debut on a debate stage Tuesday after missing the cut for the first Democratic debates, tweeted a photo of him and his son, Cam, inside the debate hall.

Every candidate does a walk-through of the debate hall, even previewing their podium placement, hours before the debate kicks off.

In the photo, Bullock is standing on the stage with his son and said he's "so grateful" to have him in the audience.

5:07 p.m. John Hickenlooper says he's 'not going to go after' Warren

Former Colorado Gov. John Hickenlooper, a candidate who needs a stand-out moment tonight to emerge from the lower-polling group of candidates, joined CNN to preview his debate strategy and talk the road ahead for his campaign.

After tweeting Monday that he plans to "go after" Sen. Elizabeth Warren, D-Mass., Tuesday night, Hickenlooper said: "I'm not going to go after her. But I do think that this notion that we can have massive government expansions is a sure-fire way to hand the election to Donald Trump. To re-elect who I would argue is one of the worst presidents we've ever had."

Despite his criticism of Warren and Sen. Bernie Sanders, I-Vt., Hickenlooper said "oh sure," when asked if he would support either candidate if they win the Democratic nomination, but that both would have a hard time winning Midwestern states like Michigan.

"I think they have a much harder time to beat Donald Trump in states like Michigan where we are. This is a state that cares about jobs and they're not for giant government programs. They're a much more conservative state than California and New York," he said.

-ABC News' John Verhovek reports from Washington, DC

4:34 p.m.: Mayor Pete says he "looking forward" to the debate

After Mayor Pete Buttigieg of South Bend, Indiana, left his walkthrough of the debate stage, he went over to St. John’s Episcopal Church near the Fox Theatre.

ABC News caught up with the small-town mayor, asking how he was feeling about the night.

He replied, "I’m looking forward to it."

-ABC News' Justin Gomez reports from Detroit, Michigan

3:43 p.m.: The Trump campaign and RNC run counterprogramming ahead of second Democratic debates

Hours ahead of the debate, the Trump campaign is out with a fresh tv ad using footage from the last debate highlighting the Democratic candidates who indicated they would provide health care benefits to undocumented immigrants.

The campaign also ran a full-page, color newspaper ad in the Detroit Free Press and Detroit News today criticizing the Democrats plans for healthcare.

The RNC is holding events in Detroit around the debates, including a roundtable on Tuesday with local business leaders promoting the USMCA Trade Deal hosted by RNC Chairwoman Ronna McDaniel.

Both the RNC and the Trump campaign's rapid response "war rooms" will be working both nights to clip moments from the debates to send to their massive emails lists and share across their social media accounts.

In terms of what the campaign is looking for during this week's debates, communications director Tim Murtaugh tells ABC News he expects the 2020 field to continue to run further to the left and embrace the four progress congresswomen of color who President Trump . and the campaign have been targeting over the last few weeks.

"They'll be scrambling to see who can advocate the most big-government socialist programs," Murtaugh said. “I’m sure everything they talk about on the stage will be Squad approved.”

-ABC News' Rachel Scott and Will Steakin reports from Detroit, Michigan

The Trump campaign has deployed a number of staffers to Detroit, including national press secretary Kayleigh MceNany, comms director Tim Murtaugh and Director of Strategic Communications Marc Lotter, who plan to each flood the airways with the campaign's reaction to the debates. RNC chairwoman Ronna McDaniel will also be on the ground.

2:33 p.m.: Bernie Sanders campaign manager shares his debate strategy

When Sen. Bernie Sanders, I-Vt., first learned about the debate lineups during CNN's random live drawing, his campaign manager, Faiz Shakir, described his reaction in an interview with ABC News Tuesday: "Well I have an ally on many of the fights that I've been waging forever" of Sen. Elizabeth Warren, D-Mass.

The campaign feels he should "focus our fire and our differences on places where she and I have been allies together and fighting certain fights," Shakir added.

With Sanders sharing center stage with Warren, Shakir detailed the senator's strategy for Tuesday's debate, saying, "Right now the strategy isn't to draw a contrast with everybody in the field, it's for him to make his case about why he's unique… So he'll make the case for himself without denigrating others. Quite frankly, you know this, we have five or six more debates to go before Iowans even vote. There will be plenty of time to draw the contrast. The debate stage will likely narrow down. Tonight isn't going to be the night where he feels like he needs to draw a contrast with Elizabeth Warren."

But prior to taking the stage, Warren rolled a new slate of endorsements, announcing she nabbed one of Sanders' 2016 backers: Rep. Raul Grijalva, D-N.M., a leading progressive on Capitol Hill who was one of a handful of lawmakers to publicly endorse Sanders over Hillary Clinton in 2016.

-ABC News' Adam Kelsey reports from Detroit, Michigan, and Benjamin Siegel from Washington, D.C.

4 a.m.: What to expect from night one of the second Democratic debates

The consecutive debates, airing on CNN at 8 p.m. ET on Tuesday and Wednesday, are expected to be more contentious, picking up where the first debates in Miami left off: when former Vice President Joe Biden was relegated to playing defense after a game-changing moment for Sen. Kamala Harris, D-Calif., and other lesser-known candidates saw spikes in fundraising and polling following a much-needed breakout performance.

For the last few weeks, campaign aides and surrogates have been sparring over policy in back-and-forth statements, cable TV appearances, and on social media, but now the candidates will have the chance to speak for themselves on their differences and present their visions for the country.

The first 10 candidates who are set to square off on Tuesday are:

Ohio Rep. Tim Ryan

Minnesota Sen. Amy Klobuchar

South Bend Mayor Pete Buttigieg

Vermont Sen. Bernie Sanders

Massachusetts Sen. Elizabeth Warren

Former Texas Rep. Beto O'Rourke

Former Colorado Gov. John Hickenlooper

Former Maryland Rep. John Delaney

Montana Gov. Steve Bullock

But beyond the two sets of polling front-runners potentially squaring off each night –Sanders and Warren sharing center stage on night one and Biden and Harris on night two -- a parade of moderates will have the opportunity to take on the progressive stalwarts and some occupying the lower fundraising tiers will have the chance to directly confront Biden, even as he prepares for attacks from all sides.

"As the clear front-runner, the attacks will once again be directed Joe Biden's way," a senior Biden campaign official told ABC News.

A day prior to the first night of debate, a new Quinnipiac University poll, released Monday, put Biden comfortably back on top of the Democratic field, with 34% support and significant distance between him and the next polling tier of Warren (15%), Harris (12%) and Sanders (11%).

On the first night, with the two liberals flanked by more moderate candidates, such as Bullock, Delaney, Hickenlooper, Klobuchar and Ryan, the ideological divide within the Democratic Party will be front and center.

Sanders and Warren might potentially spend more time teaming up to champion their transformative progressive agendas and similar vision for economic equality against criticism from the middle-of-the-road candidates, who might compete for minutes to take aim at "Medicare for All" and free public college.

And for Buttigieg -- who will stand shoulder-to-shoulder with Sanders, putting their age difference in the spotlight -- the debate will allow him a chance to restore the rising prominence he saw in the early months of the primary after several recent polls show stalling numbers among the middle of the pack.

As he prepares for the debate, a senior Buttigieg campaign official told ABC News, he expects to "put himself more out there" as he is "feeling more confident."

But for most of the candidates on stage, the stakes for this two-night showdown are much higher after the Democratic National Committee announced more stringent qualifying rules for the September and October debates: candidates will need 2% in four qualifying polls and cross the 130,000 donor mark to qualify.

Only seven candidates have qualified for the September debate, according to an ABC News analysis, including Biden, Sen. Cory Booker, D-N.J., Buttigieg, Harris, O'Rourke, Sanders and Warren. The rest of the field has only a month to go before the deadline.

This year's third Democratic primary debate will be hosted by ABC News in partnership with Univision and is scheduled for Sept. 12 and 13 at Texas Southern University, a public historically black university in Houston.

This week's debates in Michigan, the site of the heart of former Democratic nominee Hillary Clinton's loss in the Midwest after then-candidate Trump carried the state by 0.3 percentage points, also come a week after former special counsel Robert Mueller's nearly seven-hour testimony on Capitol Hill, when he raised the specter of Russian meddling in the 2020 election, after testifying that 2016 "wasn't a single attempt … they expect to do it during the next campaign."

In a new ABC News/Ipsos poll, 54% of Americans said that they are not confident in the capability of the U.S. to effectively defend itself from potential foreign government interference in the 2020 presidential election. Only 17% said they were very confident and 27% were somewhat confident.

But with concerns of foreign interference looming over the field, squabbles continue over the direction of the party. On Monday, the candidates engaged in an early preview of a debate over health care, after Harris released her Medicare for All plan, an offshoot of the Sanders' bill he introduced and she co-signed, which includes a loophole to allow private insurers to offer Medicare plans during a 10 year period.

Both Biden and Sanders' campaigns immediately railed against her new proposal.

"This new, have-it-every-which-way approach pushes the extremely challenging implementation of the Medicare for All part of this plan ten years into the future, meaning it would not occur on the watch of even a two-term administration. The result? A Bernie Sanders-lite Medicare for All and a refusal to be straight with the American middle class, who would have a large tax increase forced on them with this plan," said Kate Bedingfield, deputy campaign manager for Biden.

Sanders' campaign manager Faiz Shakir, unleashed a sharp attack on Harris, saying in a statement, "Call it anything you want, but you can't call this plan 'Medicare for All.'"