Mehmet Oz has personally spent more than Bryce Harper’s annual salary on his Senate campaign

Republican Mehmet Oz has poured $5.5 million of his own money into his U.S. Senate campaign in the last month as he tries to catch Democrat John Fetterman, according to financial filings.

That includes $4 million in the last two weeks alone in an expensive, neck-and-neck race that could decide control of the Senate. He also gave himself $1.5 million earlier in October.

Overall, Oz has given his campaign nearly $27 million, including more than $12 million since the start of July. He has spent more of his own money than any other Senate candidate this year, according to data tracked by OpenSecrets, a nonpartisan group that follows money in politics.

Oz’s personal spending is now more than the $26 million annual base salary for Phillies star Bryce Harper.

In the latest burst, Oz gave his campaign $1 million on Oct. 20, $1 million again on Oct. 24, and $2 million on Oct. 25. Those sums could help make up a cash gap against Fetterman, who had $4.5 million on hand as of Oct. 19, compared with $2.6 million for Oz.

Since the Oct. 19 reports, public disclosures of donations over $1,000 show Fetterman has raised an additional $929,000 in large donations, and Oz has raised $472,000, not counting the $4 million of his own money. The disclosures do not include smaller donations, which have been a massive part of Fetterman’s overall fund-raising.

Campaign money is crucial for TV advertising (especially in a state as vast as Pennsylvania, where door-to-door campaigning isn’t usually enough) and staff who can help turn out voters on Election Day.

Overall, Fetterman has raised almost $57 million for his campaign, roughly half of it from small donors who have contributed less than $200 total. Oz has raised less than a third of that, about $16 million, not including his own personal funds.

Oz, who made a fortune as a surgeon and daytime TV star, and who married into one of Pennsylvania’s wealthiest families, has said he “can’t be bought.” Democrats have accused him of trying to use his wealth to buy a Senate seat and argue that Fetterman’s army of small donors reflects grassroots support.