A handful of Montgomery County's most generous and reliable Republican Party benefactors have put their pocketbooks behind a surprising team this year.

Amid what is expected to be one of the hardest-fought campaigns for the county's three commissioner seats in decades, several GOP stalwarts have offered sizable donations to, of all people, Democrats.

Of the $300,000 that candidates State Rep. Josh Shapiro and Whitemarsh Supervisor Leslie Richards have raised since October, more than $37,000 - about 12 percent - has come from high-profile Republican sources.

Their early success in drawing money from across that partisan divide could signify a shift in the political winds for a county long considered the Republicans' piggy bank, or - as some local political watchers see it - another example of growing tension in the county GOP.

"We're really proud of the fact that not only Democrats think we're going to win but also a lot of Republicans and independents do, too," Shapiro said.

Those donors include:

Nan Sweeney, who, with her husband, Edward, donated $10,000 to the Shapiro-Richards campaign in March. The Blue Bell couple have supported campaigns by Gov. Corbett, to whom they gave $40,000 in the governor's race, and former presidential nominee John McCain, who received more than $10,000 of their money. Since 2008, they have also contributed more than $18,000 directly to Montgomery County's Republican committee.

William R. Sasso, who gave $5,000 to the Democrats earlier this month through his Philadelphia law firm, Stradley, Ronan, Stevens & Young. Sasso, the firm's chairman, also serves as treasurer of one of the state's largest right-leaning political action committees, the Pennsylvania Future Fund. He has donated generously from his own wallet to GOP candidates for state office. (Shapiro works for Sasso's firm.)

Gregg Melinson, who served as deputy general counsel to Republican Gov. Tom Ridge and as a member of the Future Fund's board. He and his law firm, Drinker, Biddle & Reath, where Melinson is a partner, have given more than $60,000 to Republican candidates over the last three years, including $20,000 to the Future Fund PAC. In April, they donated $500 to the Shapiro-Richards campaign.

None has contributed yet to the GOP campaign led by Commissioner Bruce L. Castor Jr. and Lower Merion Commissioner Jenny Brown.

What's behind the shift in fiscal allegiance?

Not much, Sasso said. He credited his contribution to his professional connection with Shapiro.

"We like to support valued members of the firm," he said. Sweeney and Melinson did not return calls for comment.

Others cite the one link these three heavyweights have - ties to the Future Fund committee and its chairman, Robert B. Asher.

The head of Asher's Chocolates in Souderton, he served for years as chairman of the Republican State Committee of Pennsylvania and was one of its chief fund-raisers until a 1987 conviction on perjury, racketeering, conspiracy, and bribery charges stripped him of his title.

Since his release from federal prison, he has reemerged as a major player on the state level with his Future Fund and Keystone Alliance political action committees and large campaign donations that helped push Corbett into the governor's office in November.

There is no love lost, though, between Asher and Castor, who has openly criticized the chocolate maker's influence on the party both locally and statewide.

"I would like to think there's not a connection there," Castor said of the Asherites' donations to his opponents.

Traditionally Republican donor Tom Caramanico of Haverford offered another explanation for his Shapiro-Richards support: It's always good to back a winner.

The president of the infrastructure engineering firm McCormick Taylor, Caramanico said Richards worked with his wife. And, although he credits her for suggesting their $20,000 campaign donation, he said both Democratic candidates had impressed him.

Castor's fund-raising remains low despite his status as the only incumbent in the race. He has brought in less than $35,000 to his personal campaign committee since October. His combined account with running mate Brown has raised about $25,000.

Brown, a 44-year-old municipal lawyer from Gladwyne, has landed hefty contributions on her own. Since declaring her candidacy in the fall, she has received more than $90,000 from charter-school magnate Vahan Gureghian.

That and subsequent contributions totalling $33,333 from three founding executives of the Susquehanna International Group in Bala Cynwyd account for the largest checks cut to any candidate in the race.

Their combined gifts make up 75 percent of all the money the Castor-Brown campaign has raised since October.

If early signs are any indication, they will need every penny of it. Since this month's latest filing deadline, Republicans have reported $163,000 available for spending in their various accounts. Democrats have $1.2 million, most of which came from the personal campaign coffers of Shapiro, who is coming off a November reelection bid to the Statehouse.

"This is going to be an expensive campaign," he said. "It's going to be critical to have the resources to communicate our message in a positive way to voters throughout Montgomery County."

Contact staff writer Jeremy Roebuck at 267-564-5218, jroebuck@phillynews.com, or @inqmontco on Twitter. Read his blog, "MontCo Memo," at www.philly.com/montcomemo