Billionaire Michael Bloomberg has already poured hundreds of millions of dollars into his last-minute presidential bid, but the 2020 Democratic hopeful once described multimillion-dollar ad campaigns as "obscene" spending that would "annoy people."

Bloomberg dismissed 2001 reports that he would spend upward of $30 million on his initial run for mayor in New York City. "At some point, you start to look obscene," Bloomberg told New York magazine. "There's a limited amount of ad time you can buy. It becomes dysfunctional; you annoy people with ads."

Bloomberg went on to spend $73 million on his mayoral campaign, outspending his Democratic challenger Mark Green five-to-one. The billionaire defended his excessive ad buys during his 2005 reelection campaign, denying that the ads annoyed New Yorkers during a mayoral debate.

"I guess the question is, are you bugging people?" moderator Dave Evans asked after reading Bloomberg's previous comments. "I don't think there's any evidence," Bloomberg responded.

The New York City business mogul spent a combined $261 million on his three mayoral campaigns, a figure he has now eclipsed in just the first three months of his presidential campaign. Bloomberg, who is worth an estimated $60 billion, has already spent at least $344 million on his campaign.

He has become a favorite target for progressive presidential hopefuls since launching his campaign in November. Sen. Elizabeth Warren (D., Mass.) accused the former mayor of "buying the presidency" to avoid her proposed wealth tax. The billionaire has been unapologetic about his financial advantage, focusing instead on how he is not beholden to outside influences.

Reached for comment, Bloomberg campaign spokesman Stu Loeser told the Washington Free Beacon that "not taking a cent from special interests has allowed [Bloomberg] to make decisions on what's good for the public only." He declined to specify an amount of campaign spending that Bloomberg would now find "obscene."

Bloomberg has dealt with attacks on his personal wealth in his previous political campaigns. He dismissed criticism from his mayoral rivals during his 2001 run.

"As for the other candidates, I can't help it if your problem is that you can't afford to do it yourself," he told New York magazine at the time.

Despite being a lifelong Democrat, Bloomberg ran for New York City mayor as a Republican in 2001. After narrowly defeating Green by 2 points despite his vast spending advantage, Bloomberg won reelection by a 20-point margin in 2005. He was reelected again in 2009 after the New York City Council extended the city's term limits law. Bloomberg offered Ronald Lauder, the fellow billionaire behind the legal change, an influential board position to ease concerns over the extension.

Bloomberg's Republican mayoral record has become a source of criticism among progressive presidential candidates. Democratic frontrunner Sen. Bernie Sanders (I., Vt.) called Bloomberg's stop-and-frisk policy "racist" during a Monday evening campaign stop in Tacoma, Wash., adding that it "caused communities of color, African Americans and Latinos, to live in fear and humiliation in New York City."

Bloomberg has surged in the polls during the ad blitz, which included multiple primetime commercials during the NFL playoffs and Super Bowl. He polls at third place in the RealClearPolitics average, surpassing long-established candidates, such as Warren and Sen. Amy Klobuchar (D., Minn.), as well as former South Bend mayor Pete Buttigieg, who finished among the top two in both Iowa and New Hampshire.