Billionaire businessman Michael Bloomberg has far outspent his rivals for the Democratic presidential nomination on television ads, having shelled out nearly 10 times more than current frontrunner Senator Bernie Sanders of Vermont.

The 2020 Democratic presidential hopefuls have come out swinging against the former New York city mayor, who is worth about $60 billion, as he surges in the polls while spending hundreds of millions of dollars from his fortune on his presidential bid. So far, Bloomberg has spent about $418 million on television ads, which is about $100 million more than all the other Democratic contenders combined.

Fellow billionaire and former hedge fund manager Tom Steyer has spent the second highest amount, at $194 million. Sanders comes in at a distant third with $42 million, followed by former South Bend, Indiana, Mayor Pete Buttigieg with $32 million. Senator Elizabeth Warren of Massachusetts is fourth, having spent $21 million.

"Democracy to me means one person, one vote, not Bloomberg or anybody else spending hundreds of millions of dollars trying to buy an election," Sanders, the current frontrunner for the Democratic nomination, tweeted Sunday evening.

Bloomberg, a former Republican, launched an unconventional Democratic presidential bid in late November. He has foregone campaigning in early voting states and has not asked for campaign contributions. Instead, the billionaire—who has been dubbed an "oligarch" by many critics—has dipped into his vast fortune to fund his candidacy, spending big on ads nationwide, while specifically targeting Super Tuesday voting states.

Despite not winning any delegates in New Hampshire or Iowa, Bloomberg has risen significantly in national polls. A Real Clear Politics average from recent surveys shows the wealthy businessman in third place nationwide, with 14.2 percent support. Meanwhile, Sanders is in the lead with 23.6 percent, followed by former Vice President Joe Biden at 19.2 percent.

"Sixty billion dollars can buy you a lot of advertising, but it can't erase your record," Biden said in an interview with NBC News Meet the Press on Sunday, taking aim at Bloomberg.

As Biden went on to explain, Bloomberg's record has faced growing scrutiny and criticism over the past few weeks. For example, the former New York mayor's history of significantly expanding and defending the controversial "stop and frisk" policing strategy has brought strong condemnation from prominent black and latino activists.

While Bloomberg apologized for the policy in November, just before launching his campaign, he had defended the policy, which is known to have disproportionately targeted and harmed minority communities, for many years. In 2015 remarks, he even suggested that minorities are inherently more likely to be criminals.

"Ninety-five percent of murders, murderers and murder victims fit one M.O. You can just take a description, Xerox it, and pass it out to all the cops," he said during a talk for the Aspen Institute that year.

Democratic presidential candidate billionaire Mike Bloomberg delivers remarks during a campaign rally on February 12 in Nashville, TennesseeBrett Carlsen/Getty

Bloomberg has claimed that he inherited the policing strategy and then worked to end it. But that explanation appears at odds with his public remarks and also the known data. According to statistics compiled by the American Civil Liberties Union of New York, police stops increased by about 700 percent from 2002 – when Bloomberg took office – to 2011, two years before the end of his tenure as mayor. They increased from just under 100,000 annually after he became mayor to nearly 700,000 per year in 2011, according to the ACLU data.

The candidate has also faced criticism for a reported history of making sexist and misogynistic remarks to women who worked for him, as The Washington Post reported. In one case, Bloomberg reportedly told a female employee to "kill" her unborn baby when he discovered she was pregnant, then expressing frustration about maternity leave. On another occasion, the billionaire reportedly suggested female employees should give a male colleague oral sex before he got married.

Stu Loeser, a spokesperson for Bloomberg, also told The Post that Bloomberg "did not make any of the statements" about killing the unborn baby. In a court filing, Bloomberg's lawyers denied the allegations about the oral sex comments, saying the employee did not "take advantage of any complaint or grievance procedure or opportunities provided."

"He thinks he can buy this election," Sanders said of Bloomberg at a Nevada event this past weekend. "Well, I've got news for Mr. Bloomberg — the American people are sick and tired of billionaires buying elections!"