Democratic presidential candidate, former New York City mayor Mike Bloomberg speaks to supporters at a rally on February 20, 2020 in Salt Lake City, Utah. George Frey | Getty Images

Mike Bloomberg has spent a ton of his own money running for the Democratic presidential nomination, but he hasn't been able to stop the deluge of recordings of his past controversial remarks from hitting social media. The tapes, some of which go back several years and have been reported by a variety of news outlets, reveal comments that are out of step with stances Bloomberg has been championing as a presidential candidate. They capture the candidate casting aspersions on black and Latino men, poking fun at a family struck by tragedy and deriding transgender people. The recordings have emerged as his presidential campaign grew in stature, fueled by his vast personal fortune. Some have resurfaced after his debut on the Democratic debate stage last week, when he seemed unprepared to respond to the attacks against him and his record as New York mayor.

Bloomberg's campaign did not return a request for comment from CNBC. He will return to the debate stage Tuesday night in South Carolina, where he will face off against former Vice President Joe Biden, Sen. Bernie Sanders, fellow billionaire Tom Steyer, Sen. Amy Klobuchar, former South Bend, Indiana, Mayor Pete Buttigieg and Sen. Elizabeth Warren. On and off the stage, Bloomberg's rivals have been questioning his record and presenting him as a candidate who is trying to buy the election. Bloomberg has a net worth of around $62 billion, according to Forbes, and has spent more than $500 million on campaign ads since entering the race in November. Warren last week dealt the harshest blows on the debate stage. She labeled him a "billionaire who calls women 'fat broads' and 'horse-faced lesbians'" and urged him to release women who worked for his firm Bloomberg LP from nondisclosure agreements that prevent them from discussing sexual harassment and gender-based discrimination in the workplace. Here are the past comments making the rounds on social media:

'Not a good family'

A 2019 video that surfaced Monday showed Bloomberg mocking a father and son who died from heroin overdoses. The New York Daily News, which was the first to reveal the clip, published a cover story in October 2017 about the two men, Joseph and Carlos Andrade. They both died from overdoses outside a family birthday party. TWEET In the video recorded at a business forum in Manhattan last March, Bloomberg used the tragic story to poke fun. "Daily News had a picture on the front page of a father and a son — they both OD'd at the same party. I mean, it's not a good family — craziness," he said.

'Some guy wearing a dress'

Last Tuesday, Bloomberg's campaign released a digital ad featuring designer Isaac Mizrahi praising Bloomberg's support for LGBT rights. On the same day, BuzzFeed News published a different clip from the March 2019 business forum, in which the former mayor used disparaging language to describe transgender people. TWEET In the clip, Bloomberg ridiculed presidential candidates for talking about transgender rights. "If your conversation during a presidential election is about some guy wearing a dress and whether he, she, or it can go to the locker room with their daughter, that's not a winning formula for most people," he said in the video.

'Defend the banks'

Bloomberg said at a private event in 2016 that his presidential platform would have been to "defend the banks" and called Warren, who has made a political career of criticizing Wall Street, "scary." Warren has become one of Bloomberg's biggest critics on the 2020 campaign trail. "The left is arising. The progressive movement is just as scary," he said in the recording, which resurfaced Monday. "Elizabeth Warren on one side. And whoever you want to pick on the Republicans on the right side?" TWEET Bloomberg at the event also spoke of his plan to combat income equality before society "blows up." "Well, to start, my first campaign platform would be to defend the banks," he said, "and you know how well that's gonna sell in this country." Also in the video, Bloomberg described his 2012 endorsement of President Barack Obama as "backhanded," adding that he believed Republican candidate Mitt Romney would have been a better choice. Bloomberg in his current campaign ads has been channeling Obama, presenting himself as a candidate with the former president's backing.

'It's virtually all minorities'