Former Mayor Mike Bloomberg hasn't yet announced a run for president, but he's already spending tens of millions of dollars on television campaign ads that will begin airing next week in states around the country.

One ad tracking agency put the figure around $31 million, which sets a record for the largest weekly ad purchase by a candidate.

Bloomberg aides didn't comment on the ad buy Friday. The 60-second ads are set to begin running Monday in more than 30 states around the country, including New York, California, Florida, and Texas.

The purchase dwarfs what other candidates have spent on television ads and dwarfs what some candidates have raised during the entire primary season. California Sen. Kamala Harris, for example, has raised $36 million over her entire campaign, which started earlier in the year. Bill de Blasio, Bloomberg's successor at City Hall? He raised just $1.4 million in his short-lived run for president.

One potential Democratic primary rival hit back Friday.

"I'm disgusted by the idea that Michael Bloomberg or any billionaire thinks they can circumvent the political process and spend tens of millions of dollars to buy elections," Vermont Sen. Bernie Sanders tweeted. "If you can't build grassroots support for your candidacy, you have no business running for president."

The ad buy is the latest sign Bloomberg is primed to enter the crowded Democratic primary field for president:

Bloomberg may make a formal announcement in the coming days.

The 77-year-old is one of the richest people in the world. His estimated net worth exceeds $50 billion.

Bloomberg's enormous wealth, his ties to Wall Street, and his status as a former Republican could make it difficult for him to win support among traditional Democratic primary voters. Should he run, his advisers have charted an unconventional strategy that calls for him to bypass the first four states on the primary calendar and make an aggressive play for the so-called Super Tuesday states that vote in early March.

Bloomberg's team says he's stepping toward a run because of the perceived weakness at the top of the current Democratic field, particularly in establishment-favorite former Vice President Joe Biden's candidacy.

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