HARRISBURG — Tens of millions of dollars from out-of-state donors and political action committees have poured into Pennsylvania to influence the outcome of the critical race for governor, much of it in support of Democratic nominee Josh Shapiro, a new Spotlight PA analysis shows.

Between January 2021 and mid-September of this year, Shapiro, the state’s attorney general, raised just under $51 million — roughly $25 million from out-of-state donors and PACs.

The Republican nominee, state Sen. Doug Mastriano of Franklin County, raised just under $5 million in the same time period, the vast majority of which — just over $3 million — came from donors in Pennsylvania.

Though a higher percentage of Mastriano’s campaign donations came from within the commonwealth, the two campaigns’ fundraising is so lopsided that Shapiro still has three times the number of in-state donors as Mastriano — and they provided eight times the amount of cash.

Campaign finance experts and political operatives were not surprised by the findings, as Shapiro has enjoyed strong party backing and no primary opposition, while Mastriano has struggled to attract establishment support after handily winning a crowded primary. As the Nov. 8 election draws nearer, having money on hand to spend on TV ads, staffing, and rallies ensures a campaign can reach voters.

Mastriano and Shapiro aim to replace outgoing Democratic Gov. Tom Wolf, who is constitutionally limited from seeking a third consecutive term.

The stakes of the race are high. The next governor will hold broad authority to set the policy agenda in Harrisburg on everything from education to abortion to voting rights, and the two candidates have starkly different platforms.

This race is one of the most closely watched gubernatorial contests in the country and has attracted tens of millions in donations — thanks in part to Pennsylvania’s lack of limits on campaign contributions.

To perform its analysis, Spotlight PA downloaded campaign finance data from the Pennsylvania Department of State website from January 2021 to Sept. 19, 2022, the most recent date for which information filed by the campaigns was available. Spotlight PA then used that data to calculate and map how many donors were located in different zip codes.

The Department of State separately publishes fundraising totals for candidates on its website. Spotlight PA compared Mastriano and Shapiro’s totals with ones it produced using the downloaded data and identified a roughly $1.5 million difference.

The Shapiro campaign said there was a discrepancy, but did not elaborate. The campaign did not dispute Spotlight PA’s main findings. The Department of State said the campaigns file using its online system and to “check with the committee[s] regarding any discrepancies.”

The Mastriano campaign did not reply to a request for comment.

Within Pennsylvania, Shapiro has shown particular strength in Philadelphia, Pittsburgh, and Harrisburg’s suburbs. While a majority of Shapiro’s 37,000 individual donors are from the state, a Spotlight PA analysis found that slightly more than half of his campaign contributions came from PACs and people from outside the commonwealth.

Shapiro’s expenses suggest a targeted effort to court out-of-state donors. His campaign finance reports list $240,000 in airfare — including private flights and commercial airlines — as well as hotel stays in San Francisco, Los Angeles, Washington, D.C., and Miami, among other locales.

According to Department of State data, Shapiro’s campaign has also paid a little more than $500,000 for “fundraising consulting” to a Silicon Valley-based firm run by Cooper Teboe, a Democratic operative who’s helped raise small-dollar donations for progressives and connect bigger donors with the likes of a super PAC backing President Joe Biden.

The Shapiro campaign declined to answer specific questions about his out-of-state fundraising. In a statement, Shapiro’s campaign manager Dana Fritz said that “the stakes of this race could not be higher, and this incredible and humbling support proves Pennsylvanians are ready to come together and defeat our extremist opponent.”

Mastriano’s fundraising base tightly clusters around his home base in Franklin County.

While Mastriano’s campaign boasts higher percentages of in-state donors and money, Shapiro has a wide advantage in raw totals. Shapiro has more than three times as many in-state donors as Mastriano — roughly 23,600 to 7,300 — and has raised almost eight times as much money from them — $24.5 million to $3.1 million.

Mastriano’s low fundraising total is unsurprising considering his bare-bones campaign. As Shapiro’s campaign has spent a record $42.6 million on ground staff and advertising, Mastriano has financed just one TV ad since announcing his candidacy in January 2022, and has a campaign infrastructure limited to consultants and ground volunteers.

He has tried to woo institutional donors, a strategy that included a July trip to Colorado to ask for support from the Republican Governors Association, but those efforts have been unsuccessful. Still, Mastriano has his own share of wealthy out-of-state donors.

More than seven in eight of his donors live in Pennsylvania, but about a third of his campaign funds came from a handful of supporters who live elsewhere, including $1 million from Illinois conservative megadonor Richard Uihlein and his wife, Elizabeth.

Observers expressed little surprise that large donations came from outside Pennsylvania, pointing to the increasing nationalization of local contests and the prominent place the Keystone State has in national politics.

Pete Quist, a research analyst with OpenSecrets, a nonprofit organization that tracks campaign finances and other political spending, said he was most surprised by Mastriano’s comparatively small level of out-of-state support.

“We would have expected generally for it to be a little more comparable,” Quist said. “It is not uncommon for these kinds of races to be a little lopsided. It’s a little more lopsided than I would have predicted.”

Mastriano and his allies have publicly complained about the lack of institutional backing from Republican power players. In a since-deleted Facebook Live video, Mastriano said that “nationwide Republican organizations … have not been forthcoming in supporting this campaign.”

Republican insiders have spoken about their fears that Mastriano’s extreme stances — which include his appearance at the U.S. Capitol on Jan. 6, and support for a six-week ban on abortion without exceptions — will drive away moderate voters and fail to attract the money needed to run a statewide race.

Sam Chen, an Allentown-based Republican political operative, said that donors are usually looking for two things when they write a big money check: ideological agreement, but also a chance to win.

While GOP voters who agree with Mastriano’s far-right ideology may be gravitating toward his campaign, “the activist base is not the donor base, and the donor base in both parties remains fairly centrist,” Chen said.

Chen pointed to the political donations made by a popular convenience chain. Wawa donated to GOP gubernatorial candidate Scott Wagner in 2018 and Shapiro’s Republican opponent for attorney general in 2020, campaign finance records show.

But this time around, it cut a $10,000 check for Shapiro, which “shows that in this situation, the Democrat … has claimed that centrist lane,” Chen said.

Public polling has shown Mastriano trailing Shapiro by an average of 10 percentage points, according to data journalism website FiveThirtyEight.

Joe Corrigan, a Democratic political operative based in Philadelphia, said he expected out-of-state dollars to make up a greater share of Shapiro’s war chest. Shapiro has been involved in Pennsylvania politics for decades, serving as a state representative and a Montgomery County commissioner before being elected attorney general in 2016.

“Josh has done a tremendously good job of cultivating in-state, high-dollar donors, from business executives to sports team owners to philanthropists over the past 18 years,” Corrigan said. “In a race that was always going to be about big money, no one was ever going to beat Josh Shapiro.”

Quist concurred, adding that Mastriano is in trouble because he doesn’t have the funding to keep up with Shapiro’s spending on advertising, staffing, or events. It doesn’t matter whether those critical dollars come from Pottsville or Palo Alto.

“The fundraising angle entirely favors Shapiro,” he said.

Spotlight PA is an independent, nonpartisan newsroom powered by The Philadelphia Inquirer in partnership with PennLive/The Patriot-News, TribLIVE/Pittsburgh Tribune-Review, and WITF Public Media.