Where’s the money going in the most expensive U.S. House race ever?

How exactly does a political candidate spend $16 million in two months?

On a stream of advertisements and a campaign operation not unlike that of a presidential run, it appears.

Jon Ossoff, a 30-year-old documentary filmmaker and political novice running for Georgia's 6th Congressional District seat, has energized Democrats locally and across the country as a symbol of their resistance to President Donald Trump, and his campaign donations reflect that. His campaign reported raising a record-setting $15 million between late March and the end of May, for a grand total of $23.8 million since January.

That’s more than any House campaign has ever raised, according to data from the money-in-politics website OpenSecrets.org. It tops the dollars that Speakers Paul Ryan and John Boehner, the chamber’s top fundraisers, netted from national donors looking to make a powerful friend on Capitol Hill. And it trumps the money Republicans John Kasich, Rand Paul and Carly Fiorina each pulled in during the 2016 presidential cycle.

The numbers show just how nationalized the expensive special election to replace Tom Price in the House of Representatives has become. And Ossoff's massive fundraising haul specifically shows how the surge of civic activism among Democrats has helped buoy his campaign in recent months, even as he's pivoted away from his past "make Trump furious" message.

The recent federal filings also show why many 6th District voters feel like they're being deluged by nonstop political messaging.

Ossoff spent a staggering $11.2 million of the money he raised on producing, printing and reserving airtime for political ads on television, in local newspapers such as The Atlanta Journal-Constitution and on mailers sent to voters, according to a recent AJC analysis of federal records compiled by ProPublica. And his Republican opponent, Karen Handel, who raised $4 million in the same two-month reporting period, spent more than one-quarter of the money she raised in April and May on ads, including $28,000 on yard signs.

The campaigns are hoping that the advertising can help turn independent-leaning voters their way in a district that voted for Trump by less than 2 percentage points in November.

It's unclear whether their efforts will work. Twenty-eight percent of 745 likely voters in Georgia's 6th District recently polled by the AJC said political advertisements had influenced their decision ahead of the runoff next Tuesday.

Follow the money

Ossoff’s federal filings show just how large of a campaign infrastructure he’s built since declaring his candidacy in January. He spent nearly a half-million dollars on salaries for 170 people, a massive operation for a House campaign that’s more on the scale of a presidential operation. Handel, by comparison, reported that she had 14 staff members on her rolls, a more typical size for a congressional campaign.

Just as interesting is where the two candidates’ money came from.

More than 96 percent of Ossoff's dollars and 78 percent of Handel's came from outside Georgia, according to a separate AJC analysis. Ossoff received more money from Californians and New Yorkers than from within the state, while 11 percent of Handel's donors reside in Washington, D.C., Maryland and Virginia.

The numbers are striking ones, but they paint an incomplete picture, since they are based only on what are known as “itemized contributions” and don’t include many donations under $200. The campaigns are not required to release the details of those smaller donations, so the 96 percent and 78 percent figures represent the most precise numbers available publicly.

The new financial data have fueled a new round of political attacks in the 6th. Handel has focused heavily on Ossoff’s outside donors over the past week.

“It means that an ultraliberal backed by Nancy Pelosi is trying to steal this seat,” Handel said at a recent campaign stop in Marietta, referring to the U.S. House minority leader. “We’re not going to let it happen.”’

Ossoff previously spoke out against the dearth of outside money in politics, but he said Monday that his fundraising was “necessary to raise the resources to defend myself” in the face of attack ads from GOP-aligned super PACs.

“At least as of the previous financial disclosure, many more Georgians contributed to my campaign than to Secretary Handel’s,” he said. “I’m proud of the fact that the campaign is powered by small-dollar, grass-roots fundraising.”

Both campaigns have benefited from a deluge of attack ads from the two political parties, political action committees and super PACs who have spent more than $40 million on the race. The latter can't coordinate with the campaigns, but they can spend unlimited money and don't have to report their donors.

Those outside groups have particularly helped Handel buoy her campaign in the face of Ossoff's runaway fundraising, spending more than $16.3 million on her behalf. The Ossoff camp has seen fewer such expenditures in its favor, with the majority coming from PACs aligned with the Democratic Party. Planned Parenthood was also a majority spender.

Staff writer Saurabh Datar contributed to this article.