WASHINGTON -- This is why Republican Senate candidate Bob Hugin has been able to blanket the airwaves with ads attacking U.S. Sen. Robert Menendez, making their race much closer than expected.
Hugin, a former Celgene Corp. executive, has pumped $24 million of his own money into the race, and his campaign has now outspent Menendez by almost 3 to 1, according to new Federal Election Commission filings.
Through Sept. 30, Hugin spent $22.7 million to $7.6 million for Democrat Menendez. He outspent Menendez, $14.1 million to $2.9 million, just in the last three months.
That money funded $9.3 million on media from July to September, compared with $1.8 million for Menendez.
National Democrats rushed to make up the difference, especially with most polls showing Menendez's lead within the margin of error.
The Senate Democrats' super political action committee, Senate Majority PAC, announced Tuesday it would spent $3 million on an ad in the New York City and Philadelphia markets connecting Hugin to President Donald Trump, whose campaign he financially supported.
The Democratic Senatorial Campaign Committee also has pumped $900,000 into the race.
Menendez raised more money than Hugin, $11.1 million versus $6.2 million, and had more money in the bank, $5.6 million to $3.5 million, but the challenger's personal checkbook has wiped out any financial advantage for the incumbent.
The senator's recent donors included $2,500 from Major League Baseball and $2,500 from the Joint Action Committee, a pro-Israel political action committee.
Englewood Cliffs-based NORPAC, the second-largest pro-Israel PAC by contributions to candidates, raised $14,901 for his campaign. Menendez, a strong supporter of Israel, is the top Democrat on the Senate Foreign Relations Committee.
Hugin's outside donors included $47,400 from the National Republican Senatorial Committee and $2,700 from state Assembly Minority Leader Jon Bramnick, R-Union.
He contributed $836,000 to the state Republican Committee and all 21 county parties.
The Senate campaign figures were released late Monday, the same day that former U.S. Secretary of State Hillary Clinton came to Jersey City to raise money for Menendez.
Both candidates also have received help from independent super PACs.
The pro-Hugin super PAC founded by former aides to Gov. Chris Christie, Integrity NJ, reported raising $2.4 million during the last three months, bringing its total to $4.5 million. The group spent $3.4 million on ads in support of Hugin.
The group received two $1 million contributions, from Mary Moriarty, a Chatham retiree, and Marlynn Scully, wife of major Celgene stockholder Bill Scully, who had donated $1 million earlier.
Menendez received outside help from Patients for Affordable Drugs Action, which spent $2.1 million on the race. Funding for the super PAC comes hedge fund executive John Arnold and his wife Laura, whose family foundation conducts research and offers proposals on several issues, including drug prices.
Another pro-Menendez super PAC, Leadership Alliance NJ, spent $1.2 million on behalf of the incumbent. It received $150,000 from the Committee to Build the Economy, a union-funded super PAC that supported Phil Murphy's successful gubernatorial campaign last year.
The Senate Majority PAC that will air the ads linking Hugin and Trump figured prominently in the indictment of Menendez on criminal corruption charges. Menendez's friend and campaign donor, Salomon Melgen, contributed $700,000 to the PAC, which in turn spent $580,500 on his 2012 re-election campaign.
Prosecutors alleged that the donation was a bribe in return for Menendez intervening with federal agencies on Melgen's behalf, but the judge in the trial acquitted the senator of that charge.
Jonathan D. Salant may be reached at jsalant@njadvancemedia.com. Follow him on Twitter @JDSalant or on Facebook. Find NJ.com Politics on Facebook.