(CNN) Welcome to CNN's fact check coverage of the tenth Democratic presidential debate from Charleston, South Carolina, ahead of the state's primary on Saturday.
Vermont Sen. Bernie Sanders, the current front-runner after winning the Nevada caucus, faced attacks over his recent defense of some of the actions of Fidel Castro following the 1959 Cuban Revolution. Sanders also had to defend his recently released plan to pay for his legislative proposals such as "Medicare for All," free college, and various debt forgiveness ideas.
The debate was also a chance for former New York Mayor Mike Bloomberg to bounce back from a rough performance in last week's debate, when he faced criticism over sexist comments he allegedly made in the early 1990s.
Former Vice President Joe Biden came into Tuesday's debate needing a strong performance ahead of Saturday's primary South Carolina to stay viable.
In an early exchange during Tuesday night's Democratic presidential debate, Bloomberg told Sanders that "(Russian President) Vladimir Putin thinks that Donald Trump should be President of the United States, and that's why Russia is helping you get elected."
Sanders tried to fend off the attacks by condemning Russian meddling in the 2016 election and warning Putin that he wouldn't be a Russia-friendly president.
Facts First: Bloomberg accurately pointed to a US intelligence community belief that Russia is trying to help Sanders' campaign. Russia also backed Sanders in the 2016 primary, but Sanders has publicly denounced Russian interference in US politics.
At CNN, we start with the facts. Visit CNN's home for Facts First.
Sanders acknowledged last week that US intelligence officials had informed his team that Russia was trying to help his campaign. It's not clear what Russians are doing to help Sanders, and there haven't yet been any sweeping hack-and-leak operations like the cyberattacks that hit the Democratic National Committee during the 2016 presidential campaign.
US intelligence leaders have said that Russia routinely tries to sow discord among the American public and amplify voices on the extremes of the political spectrum, to inflame divisions and undermine the stability of American democracy. Their past support for Sanders and Trump, who have both antagonized their own parties, fits into this big-picture strategy.
Separately, a senior US intelligence official, Shelby Pierson, told lawmakers earlier this month in a classified briefing that Russia was taking steps to help Trump win reelection. CNN later reported that Pierson appears to have overstated the formal assessments from the US intelligence community, and senior White House officials rebutted her comments.
The Russian government, at Putin's direction, undertook an extensive campaign in 2016 to boost Sanders' primary campaign against former Secretary of State Hillary Clinton, and to help Trump defeat Clinton in the general election. The Kremlin operation included well-funded troll farms, propaganda on social media, cyberattacks and leaks of private emails.
-- Marshall Cohen
Addressing his history with the controversial stop and frisk policy, Mike Bloomberg claimed the number of incidents decreased by 95% while he was mayor of New York.
Bloomberg said, "We let it get out of control and when I realized that, I cut it back by 95%. And I've apologized and asked for forgiveness. I've met with black leaders to try to get an understanding of how I can better position myself and what I should have done and what I should do next time."
Facts First: Bloomberg was misleading by omission, as he has been before, when he cited a 95% decline in stop and frisk. While there was such a reduction, it happened only during the last two years of his 12-year mayoralty, from the first quarter of 2012 to the last quarter of 2013, following a 605% increase in his first 10 years. Looking at his entire mayoralty, from 2002 through 2013, there was a 97% increase, not a decrease.
Bloomberg also claimed the 95% was prompted by his realization that the situation was "out of control." He does not mention that the decline began right around the time a federal judge signaled she would rule against stop and frisk, nor that he continued to be a vocal defender of stop and frisk for years after his professed realization about the harms of the policy.
You can read more about Bloomberg's history with stop and frisk here.
-- Tara Subramaniam and Daniel Dale
Massachusetts Sen. Elizabeth Warren said former New York City Mayor Michael Bloomberg previously supported Republican candidates.
"We're here in Charleston, and you know who is going to be in Charleston later this week? It's Donald Trump," Warren said. "He's going to be here to raise money for his buddy, Senator Lindsey Graham. Who funded Lindsey Graham's campaign for reelection last time? It was Mayor Bloomberg. And that's not the only right-wing senator that mayor Bloomberg has funded."
"In 2016, he dumped $12 million into the Pennsylvania senate race to help reelect an anti-choice, right-wing Republican senator," Warren added. "And I just want to say, the woman challenger was terrific. She lost by a single point. In 2012, he scooped in to try to defend another Republican senator against a woman challenger. That was me. It didn't work, but he tried hard."
Facts First: This is true. Bloomberg supported Republican Pennsylvania Sen. Pat Toomey's re-election in 2016. He supported Scott Brown in his losing effort against Warren in 2012. In 2014, Bloomberg gave money to a super-PAC supporting Lindsey Graham.
Bloomberg spent nearly $12 million in 2016 to support the reelection of Republican Sen. Pat Toomey of Pennsylvania, an ally of his on the issue of background checks on gun purchases. The New York Times also reported in November he supported Republican Sen. Lindsey Graham of South Carolina in 2014.
In 2012, Bloomberg supported Brown over Warren, saying on his radio program as mayor he supported Brown because of Brown's stance against requiring states to recognize concealed carry laws from other states.
Tonight, Bloomberg called such attacks a "side show" and not relevant to his record as mayor.
--Andrew Kaczynski
Former Vice President Joe Biden said Vermont Sen. Bernie Sanders encouraged a primary challenge to President Barack Obama in 2012.
"He said we should primary Barack Obama," Biden said. "Someone should."
Facts First: This is true. Sanders said on a radio show in July 2011 that a primary challenge to Obama would do "a good deal of service" to the country.
"So my suggestion is, I think one of the reasons the president has been able to move so far to the right is that there is no primary opposition to him, and I think it would do this country a good deal of service if people started thinking about candidates out there to begin contrasting what is a progressive agenda as opposed to what Obama is doing," Sanders said on the Thom Hartmann Show in July 2011.
"I think one of the reasons that President Obama has moved as far to the right as he has is he thinks he can go all the way and no one will stand up to him," Sanders added.
On WNYC in March 2011, Sanders said a primary challenge to Obama would "enliven the debate."
"I'm not a Democrat," he said. "I'm the longest-serving Independent. I think if a progressive Democrat wants to run, I think it would enliven the debate, raise some issues and people have a right to do that."
Sanders went on to endorse Obama in 2012.
--Andrew Kaczynski
Klobuchar claimed on Tuesday that Sanders' " 'Medicare For All' plan alone, on page 8, clearly says that it will kick 149 million Americans off their current health insurance in four years."
Facts First: While Page 8 of Sanders' bill does not specifically mention the figure cited by Klobuchar, it states that "it shall be unlawful for ... a private health insurer to sell health insurance coverage that duplicates the benefits provided under this Act." And the Klobuchar's figure is close to the latest number provided by one study. Some 153 million people are covered by private plans sponsored by their employers, according to the latest report from the nonpartisan Kaiser Family Foundation.
There are also tens of millions more who are covered by private plans through Medicare Advantage, Medicaid managed care plans and on the Obamacare individual market.
All these people would have to change their health care under Sanders' Medicare for All plan — but they would be covered by the federal plan instead.
-- Tami Luhby and Caroline Kelly
Sanders defended his sweeping plan to overhaul America's health insurance system, saying "Medicare for All" will reduce the nation's health care price tag.
"What every study out there, conservative or progressive says, Medicare For All will save money," said Sanders, who came under fire for the cost of his proposal, which has been pegged at more than $30 trillion over a decade.
Facts First: Although Sanders is correct that several studies have found Medicare for All would reduce health care spending, at least one study published last year found the opposite.
A report from the left-leaning Urban Institute Health Policy Center showed that the nation's overall health care spending would rise by roughly $7 trillion to $59 trillion over a decade if Medicare for All goes into effect. The increase would be $720 billion for 2020 alone if the policy were enacted.
That's because more people would be insured, more benefits would be covered and more medical services would be used since there'd be no cost for care.
"You will in total spend more as a nation on health care from adding all the bells and whistles that are associated with these kinds of proposals," Linda Blumberg, institute fellow, said when the study was published last October.
-- Tami Luhby
Klobuchar claimed during Tuesday's Democratic debate that a Vanderbilt University study ranked her as the most effective Democrat in the Senate and that two of her competitors for the Democratic nomination, Sens. Warren and Sanders, ranked among the bottom half of the list.
Facts First: Klobuchar is right about herself. She did rank among the most effective members of the Senate and first among Democrats, according to that study. She's also right that Warren ranked among the bottom half of Democrats. Her characterization of Sanders' ineffectiveness within the Democratic Party, though, requires clarification.
Klobuchar said during the debate in South Carolina that "according to Vanderbilt University in Tennessee, last Congress, I was the most effective Democrat in the US Senate on 15 metrics. Bernie and Elizabeth were in the bottom half. It matters -- it matters if you can actually get things done."
The Center for Effective Lawmaking at Vanderbilt evaluates the effectiveness of members of Congress and according to their evaluation of the 115th Congress (2017-2019), Klobuchar ranked as the most effective Democrat in the Senate.
What Vanderbilt calls the "Legislative Effectiveness Score" is "based on 15 metrics that take into account the number of bills a legislator sponsors, how far each of those bills advances through the legislative process from introduction to (possibly) becoming law and its relative substantive significance." The average Legislative Effectiveness Score is 1.0.
Klobuchar has a score of 2.815, ranking first among the 48 Democrats in the Senate during that time. And Warren has a score of .548 and ranks 32nd out of 48 Democrats in the Senate.
Sanders caucuses with Democrats, but since he is elected as an independent in Congress, he was not ranked among those within the party as Klobuchar suggested. Sanders has a score of .159.
Sanders' and Warren's rankings are below 1.0, the average among all members of Congress.
-- Maegan Vazquez
Early in the debate, Sanders used an inaccurate figure that had been provided to his campaign by a progressive think tank that, among other things, keeps track of the fortunes of billionaires.
"In the last three years, last three years, billionaires in this country saw an $850 billion increase in their wealth," Sanders said.
Facts First: The think tank that provided the figure says it is wrong, and says it takes responsibility for the error.
Sanders was relying on a figure from the Institute for Policy Studies, according to the think tank senior scholar Chuck Collins but the number was inflated. "We informed Senator Sanders that US billionaires increased their wealth since Trump's election by $850 billion. Our updated number is $710 billion, an increase of 30 percent," Collins told CNN during the debate.
"Senator Sanders was accurately using information that we provided, so we at Institute for Policy Studies are responsible for the error," Collins added.
He said that in 2016, there were 541 US billionaires with wealth totaling about $2.4 trillion. In 2019, he said, there were 607 US billionaires with wealth totaling about $3.1 trillion.
Collins said he informed the Sanders campaign on Tuesday morning that there had been an error, after CNN contacted the campaign to ask for the source for the $850 billion number. It is not clear, though, whether Sanders himself was informed of the error prior to the debate.
There is no doubt that the wealthiest Americans have gotten wealthier under Trump, though others have also gained.
According to the Federal Reserve, the combined wealth of the top 1% of American households increased 18% from the fourth quarter of 2016 to the third quarter of 2019 -- from $29.18 to $34.53 trillion. The combined wealth of the bottom 50% of households increased 55%, but from a much smaller starting point -- from $1.08 trillion to $1.67 trillion -- and spread out across many more households.
-- Daniel Dale
Bloomberg on Tuesday took a swing at President Donald Trump when the debate turned to the deadly coronavirus, which is spreading around the world and sparked a massive selloff this week in the stock market.
"The President fired the pandemic specialist in this country two years ago," Bloomberg said. "So, there's nobody here to figure out what the hell we should be doing. And he's defunded (the) Centers for Disease Control (and Prevention), CDC, so we don't have the organization we need."
Facts First: Bloomberg's statement is mostly accurate. The Trump administration eliminated key White House positions that handled global health issues, and, while it didn't fully "defund" the CDC, the administration did cut funding to the federal agency.
CNN reported last month that the Trump administration's response to coronavirus was being coordinated by the White House's National Security Council. But the NSC does not currently have a person dedicated to overseeing global health issues. That position was restructured in 2018, and a current official with a similar purview has less authority than the former official.
A Foreign Policy report late last month stated that "the United States has never been less prepared for a pandemic," primarily because the Trump White House fired the entire chain-of-command that handled responses to pandemics.
The Trump administration did make cuts to the CDC, which specifically hit epidemic prevention activities when they were imposed in 2018. Because of those reductions, the CDC dramatically reduced the number of countries where its staff works to prevent, detect and respond to infectious disease threats.
During the debate, Trump tweeted that the "CDC and my Administration are doing a GREAT job of handling Coronavirus," and attacked Democrats for criticizing his response to the virus.
-- Marshall Cohen
Biden said that Sanders voted against the so-called Brady Bill, a key piece of gun control legislation which ultimately passed in 1993 after a long debate that included whether to extend waiting periods for gun purchases.
According to Biden, longer waiting periods would have prevented mass shooter Dylann Roof from obtaining the weapon he used to murder nine people at Charleston's historically black Mother Emanuel AME Church in 2015.
"Bernie voted five times against the Brady Bill," Biden said.
"I'm not saying he's responsible for the nine deaths, but that man would not have been able to get that weapon," Biden said.
Facts First: It's true that Sanders voted against the Brady Bill five times, but it's unclear how a longer waiting period would have prevented Roof from purchasing the firearm.
Sanders voted against versions of the Brady Bill that included seven- and five-day waiting periods for purchasing firearms.
Roof, who was not legally allowed to purchase a firearm due to a pending illegal drug possession case, was able to buy a handgun because the database that was supposed to flag Roof's pending case, the National Instant Criminal Background Check System managed by the FBI, didn't include the pending case details. Due to a clerical error, the information was never submitted to that database.
Roof's background check took longer than three days to complete and so the gun shop owner was allowed to sell him the gun after the three days passed. Because this error wasn't discovered until after the shooting, when the FBI began investigating Roof, it's unclear how a longer waiting period would have prevented Roof from passing the background check.
-- Holmes Lybrand
During the debate, Biden and Klobuchar argued over who authored gun control legislation aimed at protecting women.
"I am the author of the bill to close the boyfriend loophole that says that domestic abusers can't go out and get an ak-47," Klobuchar said.
"I wrote that law," Biden replied.
"You didn't write that bill," Klobuchar said.
"I did," Biden reiterated.
Facts First: Klobuchar and Biden are talking about two different pieces of legislation.
Klobuchar has introduced legislation that would make it legally clear that dating or more casual partners who were convicted of a misdemeanor for domestic violence (as well as convicted stalkers) would not be allowed to own a firearm.
As a senator, Biden sponsored the Violence Against Women Act, legislation that aimed, in part, at improving how prosecutors and police worked to combat domestic violence. As a White House memo in 2014 describes, "The bill established new federal crimes of interstate domestic violence and stalking, doubled penalties for repeat sex offenders, and sparked the passage of laws at the state level to protect victims."
-- Holmes Lybrand
In a back-and-forth with Vermont Sen. Bernie Sanders about gun control, Biden said, "150 million people have been killed since 2007 when Bernie voted to exempt the gun manufacturers from liability."
He added, "More than all the wars, including Vietnam, from that point on. Carnage on our streets."
Facts First: Biden's number is incorrect. When CNN asked about it, his campaign said he misspoke. He's also wrong about when the vote occurred. It was 2005, not 2007. Fewer than half a million people in the US have died by gun violence since 2005 -- but he's correct that it's more than the number of military casualties since the Vietnam conflict.
Data from the Centers for Disease Control and Prevention shows that 474,993 people died because of a firearm injury between 2005 and 2018, the latest data available. That it includes intentional and unintentional deaths.
A spokesperson for the campaign said that Biden meant to say 150,000 -- and was referring to the number of homicides. That number checks out, if you're counting from 2007 . But the Centers for Disease Control and Prevention says there were 173,325 homicides committed with firearms between 2005 and 2018.
Whether you count homicides only, or all deaths, more people have died from gun violence since 2007 than military deaths in US wars since the Vietnam Conflict began in 1964. A Congressional Research Service report said 67,000 military members were killed in wars since then.
-- Katie Lobosco
On Tuesday night, Sanders had to defend his numerous comments praising elements of the Cuban communist regime, which have recently gained attention following a 60 Minutes interview and a CNN townhall. Sanders said that while he has admired aspects of the Cuban revolution, he has also condemned authoritarianism in the country.
"I have opposed authoritarianism all over the world," Sanders said, likening his comments on Cuba to comments made by then-President Barack Obama.
"Of course you have a dictatorship in Cuba," he added. "What I said is what Barack Obama said in terms of Cuba, that Cuba made progress on education. What Barack Obama said was they made great progress on education and healthcare. That was Barack Obama."
Biden shot back at Sanders, saying that Obama did not praise the Cuban government. Biden then accused Sanders of not condemning the Cuban government.
"This man said that, in fact, he thought it was -- he did not condemn what they did," Biden said.
"That is untrue, categorically untrue," Sanders responded.
Facts First: Sanders is correct that he has condemned authoritarianism in Cuba, but over nearly four decades, he has also repeatedly praised aspects of Cuban society. President Obama did as well as part of his effort to open relations between the US and the communist island.
First, here's what President Obama said about Cuba in March 2016.
"And I said this to President (Raul) Castro in Cuba. I said, look, you've made great progress in educating young people. Every child in Cuba gets a basic education-- that's a huge improvement from where it was. Medical care -- the life expectancy of Cubans is equivalent to the United States, despite it being a very poor country, because they have access to health care. That's a huge achievement. They should be congratulated."
In an interview from the 1980s, Sanders argued that the longevity of the Castro regime was not solely due to its repressive tactics, but a genuine base of support in Cuba.
"You may recall way back in, when was it,1961 they invaded Cuba and the, everybody was totally convinced the Castro was the worst guy in the world. All the Cuban people were going to rise up in rebellion against Fidel Castro," Sanders said, discussing the logic behind the Kennedy administration's failed Bay of Pigs coup. "They had forgotten that he educated the kids, gave them health care, totally transformed the society."
In 1989, according to the Burlington Free Press, Sanders criticized the "one-party regime" and "censorship" of the press in the country, but also praised other aspects of the country.
"Under (Cuban leader Fidel) Castro, enormous progress has been made in improving the lives of the poor people (and) of the working people," Sanders said. "On the other hand, in terms of democratic rights, there are enormous deficiencies."
As a third-party candidate for Vermont governor in 1976, Sanders scoffed at the idea the type of socialism he supported was similar to authoritarianism in China, Cuba, and Russia.
"We live in Vermont, not in Cuba, China or Russia," Sanders said. "We have to do what we can to meet the needs of the people here. Anyone who says I'm following Mao's method, or Cuba's or Russia's is a lunatic."
-- Andrew Kaczynski