(CNN) Welcome to CNN's fact check coverage of the Democratic presidential debate hosted by NBC News and MSNBC and held in Las Vegas ahead of Saturday's Nevada caucuses.
Tonight was the ninth presidential debate, and the first that presidential candidate Mike Bloomberg qualified for. Many of the other candidates on stage attacked the former New York mayor and billionaire on his previous policies, like "stop and frisk" and his campaign's significant ad spending.
For candidates Sen. Elizabeth Warren and former Vice President Joe Biden, the debate offered a chance to turn around their poor showings in New Hampshire and Iowa, while Sen. Bernie Sanders looke to keep his lead in national polling and overtake former South Bend, Indiana, Mayor Pete Buttigieg's delegate lead.
CNN fact checked candidate's claims raging from policy projections, their work history and alleged accolades and attacks on those sharing the stage.
Biden's claim about Bloomberg calling Obamacare a "disgrace"
Biden said Bloomberg called Obamacare "a disgrace" after it passed.
"The mayor said, when we passed it, the signature piece of this administration, it's a disgrace," Biden said. "They're the exact words. It was a disgrace. Look it up, check it out, it was a disgrace."
Facts First: This is true.
Bloomberg did call the final Obamacare bill "a disgrace" during a July 2010 event at Dartmouth College, just months after the law's passage. Bloomberg added that the law did "absolutely nothing to fix the big health care problems" calling it just "another program that's going to cost a lot more money."
Bloomberg defended himself at the debate, saying, "I was in favor of it. I thought it didn't go as far as we should," comments his campaign also made to CNN's KFile on Sunday. His campaign pointed to comments he made in 2013 on a radio program after the bill's passage as a sign of his support. "Congress passed this, so let's try it at least," Bloomberg said.
"Some parts of Obamacare I don't think will work, I don't think is fair, I don't think is intelligent, whatever. But I don't have a better answer other than let's try this," Bloomberg also said.
-- Andrew Kaczynski
Klobuchar on her record in red districts
As she has in prior debates, Klobuchar asserted Wednesday that she's won elections in Republican-held areas.
"I'm the one on this stage that had the highest voter turnout of any state in the country when I led the ticket, as well as bringing in rural and suburban voters. And I've done that as well," she said. "And I'm the only one with the receipts to have done that in Republican congressional districts over and over again."
Facts First: Partly true. Minnesota had the highest voter turnout rate of any state during each of her Senate campaigns, but Klobuchar is not the only candidate who has won Republican-held congressional districts
Biden, who spent most of his career as the senator for Delaware, won in Republican congressional districts.
Biden first won the 1972 election to be senator from Delaware and was repeatedly re-elected to serve in that position by considerable margins until he became vice president in 2009. During that time, Delaware's sole congressional district was held by Republicans from 1973 to 1983, and from 1993 to 2011.
Turnout was highest in Minnesota in years when Klobuchar ran. In her three election years, Minnesota had the highest state voter turnout nationwide.
-- Caroline Kelly
Buttigieg on hostility of Sanders followers
Buttigieg criticized Sanders' handling of bullying by some of his online followers and asked, "Why did this pattern arise? Why is it especially the case among your supporters?" Sanders retorted, "I don't think it is especially the case."
Facts First: While online harassment occurs across the political spectrum and the scope of the issue is hard to quantify, Sanders has battled allegations since 2016 that his supporters engage in harassment. A digital media expert who looked into it told CNN that the hostility from some Sanders' followers outweighs that of his Democratic rivals.
Sanders leads the Democratic field in raw measures of engagement on social media with more than 10 million followers on Twitter and 5 million likes on his campaign's official Facebook page.
Among unofficial Facebook pages created by supporters of Democratic candidates, Sanders also leads with 2.5 million followers and roughly 58,000 posts between November and January, more than that of all other Democratic candidates combined, according to data from the analytics company CrowdTangle.
"Anytime you have far greater numbers, you have far greater potential for harm," said Ben Decker, who runs the digital investigations consultancy Memetica. Decker, who has monitored Facebook groups supporting Democratic candidates and who previously spoke to CNN, said he has observed higher levels of online harassment among Sanders' followers relative to those of his Democratic rivals.
In January, the Washington Post reported that Sanders supporters had "weaponized Facebook to spread angry memes" about other Democratic contenders and cited data showing that since 2019, almost 3,000 active pro-Sanders Facebook pages have generated more than 290 million shares, likes or other actions.
At a CNN town hall Tuesday, Sanders said members of his campaign have also experienced harassment, and he disavowed all such behavior. "I do not believe in online bullying," he said. "End of discussion."
-- Curt Devine