Thursday's debate was hosted by PBS and Politico, and came a day after the House of Representatives impeached President Donald Trump. It also came the same day the House voted to approve Trump's US-Mexico-Canada Agreement.

Just a month and a half before the Iowa caucuses, the three-hour debate offered candidates a chance to delve more deeply into their policy disagreements than they had in their five previous clashes.

Only seven candidates met the party's thresholds for qualification this time: former Vice President Joe Biden, Vermont Sen. Bernie Sanders, Massachusetts Sen. Elizabeth Warren, South Bend, Indiana, Mayor Pete Buttigieg, Minnesota Sen. Amy Klobuchar and businessmen Andrew Yang and Tom Steyer.

Buttigieg fires back at Warren over her earnings

Buttigieg responded to an attack from Warren about his fundraising by reminding viewers that he is the least well-off candidate in the race.

"Senator, your net worth is 100 times mine," Buttigieg said after Warren highlighted Buttigieg's attendance at a fundraiser with $900 bottles "in a wine cave full of crystals." Buttigieg was referencing a Forbes magazine article that rated the net worth of every candidate. The magazine estimated Warren's net worth at $12 million and his at just $100,000.

Facts First: It's clear that Buttigieg earns far less than Warren, but documents publicly released so far don't offer comprehensive detail on candidates' net worth.

Buttigieg, the youngest candidate, is the lowest earner on the debate stage, according to a review by CNN of tax returns of the presidential Democratic candidates. With his husband Chasten, Buttigieg had an adjusted gross income of $152,643 in 2018

By contrast, Warren reported an adjusted gross income of $846,394 in 2018 -- $324,687 of which came from her books.

In the past five years, Warren has earned the most from her writing, pulling in $2.8 million from her work, including the best-seller "A Fighting Chance," as well as ongoing royalties from writing academic textbooks.

— Donna Borak and Anna Bahney

Sanders on campaign contributions to Joe Biden

During an exchange with Sanders about campaign donations from billionaires, Biden said, "The largest contribution I've accepted is $2,800, which is allowed under the law."

Facts First: Biden was correct about the maximum donation to his campaign, and about the law -- $2,800 is the Biden was correct about the maximum donation to his campaign, and about the law -- $2,800 is the legal maximum a person can donate to any candidate in this primary. But Biden omitted something significant: he is backed by a super PAC . Though we don't yet have information about donations to this super PAC -- the group, called Unite the Country, was only formed in late October -- all super PACs can accept donations of any amount.

Like other super PACs, Unite the Country is separate from the campaign. But it was formed by a team that included longtime Biden advisers after the campaign publicly abandoned its previous opposition to receiving support from an outside group.

While Biden's campaign declined to comment on Thursday, in October his deputy campaign manager Kate Bedingfield issued a statement signaling the campaign's change of position.

Bedingfield said that Biden would, as President, seek a constitutional amendment to overturn Citizens United, a 2010 Supreme Court decision that led to the creation of Super PACs. But she said that, given the expected amount of campaign spending by Trump and given the "crisis in our politics," it is "not surprising that those who are dedicated to defeating Donald Trump are organizing in every way permitted by current law to bring an end to his disastrous presidency."

Trump's 2016 and 2020 campaigns have been aided by a variety of Super PACs. A leading pro-Trump Super PAC, America First Action, plans to spend tens of millions in support of Trump's re-election campaign; it has set a public goal of raising $300 million.

— Daniel Dale

Yang on depression levels

Yang contrasted the strength of the US economy with Americans' well-being and said "depression, financial insecurity, student loan debt, even suicides and drug overdoses" are at record highs. "It has gotten so bad that our life expectancy as a country has declined for the last three years because suicides and drug overdoses have overtaken vehicle deaths for the first time in American history."

Facts First: Yang is stretching these sad facts. He's correct that life expectancy declined over a three-year period and while studies indicate these rates have risen in recent years, it's impossible to say they're at record highs.

It's true that student loan debt, which has climbed to $1.5 trillion , has reached record levels

Drug overdose deaths increased between 1999 and 2017, but provisional data posted by the CDC earlier this month suggest that rate fell slightly last year -- down to an estimated 69,000 deaths from about 70,000 the year before

Life expectancy decreased between 2014 and 2017, falling from 78.9 to 78.6, according to the CDC , which attributed the slight downtick to drug overdoses and suicides.

A study by the by the National Safety Council found that the "odds of death" for suicide and opioid overdose were higher than motor vehicle crashes. But Yang is incorrect in the way he compared this to all of US history. There were only 36 highway fatalities in the year 1900 , for example.

— Curt Devine

Klobuchar on Hillary Clinton margin of victory

Klobuchar said, "If you look at the poll[s], at the state that knows me best, and that is the state of Minnesota, it showed in the state that Hillary had her lowest margin of victory, it showed that I beat Donald Trump by 18 points."

Facts First: She's basically right about the polls, but she's wrong about the 2016 election results.

In 2016, Hillary Clinton barely defeated Donald Trump in Minnesota, winning by 1.6 percentage points. It was extremely close, but it wasn't her tightest margin of victory, as Klobuchar claimed. That state was New Hampshire, where Clinton won by about 0.4%.

Looking ahead to 2020, Klobuchar accurately cited a recent poll from her home state of Minnesota. An October poll from the Minneapolis Star Tribune, the largest newspaper in the state, found that Klobuchar would have a 17-point lead over Trump, which is a larger lead over the President than her Democratic opponents. (The poll had a 3.5% margin of error.)

— Marshall Cohen

Yang links Trump's 2016 victory to shifts in manufacturing employment

Yang, whose campaign has focused on the threat automation poses to US workers, claimed that President Donald Trump's 2016 win was in part because "we blasted away 4 million manufacturing jobs" -- and further claimed that 40,000 manufacturing jobs have been lost in Iowa.

Facts First: This is true, but only if you look back as far as the early 2000s. US manufacturing employment actually went up during President Barack Obama's second term, and that's continued under Trump.

The US lost 4.4 million manufacturing jobs between January 2000 and November 2019. The sharpest declines during this nearly two-decade stretch happened during the 2001 recession and between late 2007 and mid-2009 -- that is, during the financial crisis.

Similarly, Iowa lost jobs during that period, shedding a total of 20,900 jobs, according to the Bureau of Labor Statistics.

But looking at a more recent time frame, manufacturing jobs increased, improving from a net loss of 5.8 million jobs from 2000-2010 . During Obama's second term, and following Trump's election, the sector added positions.

The Bureau of Labor Statistics showed 385,000 additional manufacturing jobs were added between January 2013 and January 2017.

Since Trump took office, the sector has added another 497,000 jobs.

Iowa showed the same increasing trend for manufacturing positions , both in the lead-up to Trump's election and since he took office.

That said, American factories have been suffering this year. The trade war has been weighing on business investment, demand for products and also hiring. The US manufacturing sector contracted for four months in a row through November , according to the Institute of Supply Management.

— Anneken Tappe

Biden on 1 million Uyghurs

Asked about steps the US could take to address the rise of China, Biden said: "What we have to make clear is that we, in fact, are not going to abide by what they have done. A million Uyghurs, as you pointed out, Muslims, are in concentration camps. That's where they are right now. They're being abused."

Facts First: Concrete numbers on this issue are hard to come by. But the latest numbers from the US government and human rights organizations support Biden's claim.

The United Nations estimates at least 1 million of the Muslim minority Uyghurs are being held in "political camps for indoctrination." In 2018, the US State Department estimated that anywhere from 800,000 to more than 2 million individuals are detained in these camps, which includes Uyghurs as well as members of other Muslim minority groups.

In July 2019, a senior Chinese official said most of the detainees had been released but refused to provide updated figures on how many people remained in the camps.

Documents leaked to The New York Times in November deeply undermine China's claims the detention camps are for voluntary re-education purposes, but representatives of the Chinese government continue to dismiss the accuracy of such documents.

—Tara Subramaniam

Klobuchar on GOP efforts to suppress African-American votes

Klobuchar accused Republicans of trying to improve their chances in future elections by suppressing the African-American vote, which has historically gone in favor of Democrats by large margins.

"They have made it harder for African-Americans to vote," Klobuchar said. "As one court said, 'discriminated with surgical precision.'"

Facts First: Klobuchar got the quote right, and the rest of her claim is largely true. Republican-controlled legislatures across the country have passed laws aimed at preventing voter fraud that have made it harder for African-Americans to vote, and some of these laws have been declared unconstitutional by federal judges.

The federal Commission on Civil Rights said in a 2018 report that there was a surge in state laws that make it harder for minorities to vote. The report highlighted laws signed by Republican governors in states like Alabama, Arkansas, Missouri and several others. Those laws, which were aimed at preventing voter fraud, required voters to show government ID before casting a ballot, scaled back the availability of early voting, and eliminated voter registration options.

Klobuchar got the quote right. A federal appeals court struck down North Carolina's voter ID law in 2016, and in their ruling, they said the law would "target African-Americans with almost surgical precision." Alluding to the law's racial motivations, the court said it "impose[s] cures for problems that did not exist."

A separate federal court ruled that a similar law in Texas discriminated against black and Latino voters.

Klobuchar said she'd tackle the problem by trying to "stop the purging" of voters from the rolls, which became a major issue this month after purges in Wisconsin and Georgia.

But that might be easier said than done: Elections are run by the states, not the federal government. So if Klobuchar becomes president, she'd have limited influence over state officials who administrate elections and have overseen the recent purges.

— Marshall Cohen

Yang and Sanders on black maternal mortality

In response to a question about being the only non-white candidate on stage, Yang pointed to statistics on disenfranchisement among communities of color, noting that "if you're a black woman, you're 320% more likely to die from complications in childbirth." Sen. Bernie Sanders later echoed the claim, asserting that "black women die three times at higher rates than white women."

Facts First: The candidates are correct -- black women die from childbirth complications more than three times as often as do white women, according to government medical data.

According to a report released in May using Centers for Disease Control data from 2011 to 2015, black women experienced 42.8 pregnancy related deaths for every 100,000 live births -- 3.3 times as high as the 13.0 such deaths for every 100,000 live births among white women.

The study showed that about 700 women die due to pregnancy-related complications in the United States each year.

— Caroline Kelly

Sanders on arms spending

Calling for an international effort to fight the climate crisis, Sanders criticized global spending on weapons.

"And maybe, just maybe, instead of spending $1.8 trillion a year globally on weapons of destruction, maybe an American president -- i.e. Bernie Sanders -- can lead the world. Instead of spending money to kill each other, maybe we pool our resources and fight our common enemy, which is climate change," Sanders said.

Facts First: Sanders was speaking imprecisely. The $1.8 trillion figure represents all global military spending in 2018, not spending on weapons in particular.

Upon issuing the $1.8 trillion figure in April, the Stockholm International Peace Research Institute, an international authority on military spending, said it "discourages the use of terms such as 'arms spending' when referring to military expenditure, as spending on armaments is usually only a minority of the total."

"Military expenditure refers to all government spending on current military forces and activities, including salaries and benefits, operational expenses, arms and equipment purchases, military construction, research and development, and central administration, command and support," the Institute said.

— Daniel Dale