A Wall Street-backed super PAC is giving Republican Dave McCormick a financial edge over U.S. Sen. Bob Casey

The campaigns and outside spending groups trying to influence Pennsylvania’s nationally watched U.S. Senate race spent a combined $234 million through the end of September, with Republican Dave McCormick benefiting from a $21 million edge over Democratic incumbent Bob Casey.

Casey’s campaign had spent $44.6 million on the race through the end of September, while McCormick’s doled out $22.2 million, according to an analysis of campaign finance data by the political transparency nonprofit OpenSecrets.

In the most recent reporting period, from July 1 to Sept. 30, Casey’s campaign raised $16 million, and McCormick’s campaign took in $7.6 million, according to the most recent reports filed with the Federal Election Commission.

But McCormick holds a massive advantage when it comes to spending by outside groups like super PACs, which are allowed to raise money in unlimited amounts, sometimes from anonymous donors, but are prohibited from coordinating with the candidates’ campaigns.

Super PACs and other groups spent $108.3 million to promote McCormick or attack Casey through September, while Casey benefited from $65 million in outside spending.

» READ MORE: McCormick narrows gap with Casey in latest poll

The biggest non-campaign spender in the race is Keystone Renewal PAC, which has spent $45.3 million on the race. The group is solely dedicated to electing McCormick, a former hedge fund CEO, and it is backed primarily by uber-wealthy individuals in the finance sector.

It is the only outside group dedicated solely to this Senate race, and it is the primary reason that McCormick, in just his second run for office, has been able to compete financially with a three-term incumbent. (McCormick ran for Senate in 2022 but lost in the GOP primary.)

Given that both sides are well-resourced, it’s unlikely that McCormick’s financial advantage will make the difference in the increasingly close race. Super PACs pay higher rates to place TV ads, and challengers often need to spend more to increase voters’ awareness of them.

But money keeps pouring in, and Pennsylvanians can expect to continue to be inundated with ads on the Senate and presidential races ahead of the Nov. 5 election.

» READ MORE: China, Pa. teachers, and a ‘cult-like’ culture: Why Dave McCormick’s time at Bridgewater, the world’s largest hedge fund, matters for his Senate run

“This fundraising quarter shows that the people want to send Bob Casey back to Washington,” Casey campaign manager Tiernan Donohue said in a statement. “While his opponent is backed by out-of-state billionaires, Bob Casey is backed by the working people of Pennsylvania.”

A majority of both candidates’ financial support comes from outside Pennsylvania, which is common in modern Senate races. But it’s likely that McCormick more heavily relies on donors from elsewhere because a greater portion of his support comes from outside spending groups with no local ties, and because a slightly higher percent of his campaign cash in previous reporting periods has come from elsewhere, according to OpenSecrets.

In a statement, McCormick spokesperson Elizabeth Gregory criticized Casey as a “career politician” who has sided with President Joe Biden’s administration in 98% of votes.

» READ MORE: Why Sen. Bob Casey has changed his positions on abortion and same-sex marriage — and why his opponent doesn’t talk much about it

“It’s time for a change,” McCormick said, “and as a 7th-generation Pennsylvanian, combat veteran, and PA job creator, Dave McCormick will bring new leadership and fresh ideas to the Senate.”

A majority of the the outside spending in the race has come from PACs controlled by each party’s Senate leadership.

The Senate Majority PAC, a Democratic super PAC, has spent $39.1 million to boost Casey, and the Democratic Senatorial Campaign Committee has chipped in $10.2 million. The former group plans to spend another $16 million before Election Day on Nov. 5 “to continue holding Dave McCormick accountable” on issues including abortion rights, spokesperson Hannah Menchhoff said.

The Senate Leadership Fund, the GOP’s super PAC, has spent $38.1 million on behalf of McCormick, and the National Republican Senatorial Committee has added $2.5 million.

The only other independent expenditure committee that has spent more than $10 million in the race is Americans for Prosperity Action, a the libertarian-leaning super PAC associated with conservative billionaire Charles Koch. The group is funding advertising and get-out-the-vote efforts in Pennsylvania, and it spent $15.9 million on the Senate race through September.