Bill McSwain got a major boost from a conservative group that spent millions of dollars to promote his campaign for governor — and he has the most cash in the bank in the nine-candidate Republican primary field.

Dave White spent most of the $3 million he lent his campaign last year — and then chipped in $1 million more to his war chest. Lou Barletta and Doug Mastriano struggled to raise as much money as other top contenders, but they remain the best-known Republican candidates and possibly the front-runners.

Five weeks before the primary election, no single Republican candidate for governor has taken command of the race. But campaign-finance reports filed this past week offer clues as to which contenders have a shot to win the party’s nomination on May 17.

Whoever wins will take on State Attorney General Josh Shapiro, the presumptive Democratic nominee, who had $16 million in his campaign account at the close of the three-month period ending March 28 — a huge financial advantage over his prospective GOP rivals.

The finance report filings came as the race took a negative turn. McSwain’s campaign last week started airing a TV ad blasting Barletta, Mastriano, and White as “career politicians” who couldn’t be trusted. That salvo prompted White’s campaign to call McSwain a flailing candidate.

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It remains to be seen whether any amount of television ads can dislodge Mastriano, a state senator, and Barletta, a former congressman, from the top of the polls. Both staunch allies of former President Donald Trump, they have consistently led the field in surveys of Pennsylvania Republican primary voters, though most say they are undecided.

“Both Doug and myself have not had one ad on TV and in all the polling we’ve been at the top,” Barletta said during a debate this month. “It shows that name ID and people knowing who you are is a big deal.”

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But McSwain, for one, has the money to try.

He raised more than $1.4 million last quarter — almost as much as he raised all of last year. And he was able to save much of his haul for the home stretch, thanks to an allied political group, Commonwealth Leaders Fund, that spent $5.9 million on TV ads and other expenses to support McSwain. Commonwealth Leaders Fund’s biggest donor is the billionaire investor Jeffrey Yass, cofounder of the Bala Cynwyd-based trading firm Susquehanna International Group.

McSwain, a former U.S. attorney, spent about $546,000 and ended the quarter with $1.7 million in the bank.

Other candidates had to spend more to keep pace. White, a former Delaware County councilman who owns an HVAC contracting firm, raised almost $800,000 on top of the $1 million he lent his campaign. He spent $4.1 million and had $171,000 at the beginning of April — about one-tenth of McSwain’s available cash.

White, however, may be able to tap another personal loan to catch up.

The other big spender in the first quarter was state Senate leader Jake Corman. After leading the field in fund-raising last year — with $3 million to start 2022 — he struggled to keep pace in the last three months, raising almost $600,000. Corman spent almost $2.4 million and entered April with just $270,000 in the bank.

Mastriano raised the least amount of money among the top contenders — reporting about $373,000. He spent most of that but reported having more than $1 million to end the quarter, thanks to his fund-raising last year.

Barletta, by contrast, began the year low on cash and didn’t do much to change that. He raised $431,000 and spent about three quarters of that. He reported about $356,000 in his account at the beginning of the month. But Barletta, who ran statewide in 2018 as his party’s nominee for U.S. Senate, already has strong name recognition with voters and may not need as much money as his lesser-known rivals.

None of the remaining candidates — heart surgeon Nche Zama, former U.S. Rep. Melissa Hart, political consultant Charlie Gerow, and Montgomery County Commissioner Joe Gale — raised more than $60,000 over the last three months. Of those candidates, Gerow reported the most money in the bank, with almost $180,000.