And yet Guzzardi, known for his financial support of conservative, anti-establishment candidates, has always said he can beat Corbett.
That belief was bolstered when he collected enough signatures to qualify for the ballot, and again when GOP members took him to court last month, challenging those signatures. As of Friday, a judge had not ruled on the matter.
Party members say they want Guzzardi out because he didn't follow campaign rules. Guzzardi and his supporters smell fear.
"At the outset, this was not a 'send a message' campaign," Guzzardi said in an interview Wednesday. "Corbett is vulnerable in a primary. Republican voters all know that he has not accomplished a single thing . . . He is going to lose against any Democrat, and much less a top-tier Democrat."
He added, "If they don't see me as a threat, why are they going to all this trouble?"
Guzzardi, 69, who made his money in real estate, decided to run late last year to offer a choice to conservative voters. He is passionate about reforming the party, and over the years has donated thousands of dollars to political causes and candidates, including Democrats, campaign records show.
An advocate for small government, Guzzardi has described himself as the "friend of the forgotten taxpayer." With no staff, he runs his campaign through online mailings from his home, as well as community outreach. He has pledged not to use his own money or seek contributions. He collected more than 3,000 signatures from supporters he met at farmer's markets, gun shows, and other events around the state, and has so far reported raising $4,500.
With his glasses and snowy white hair, Guzzardi has a mild-mannered look. He dresses in button-down shirts or blue blazers with gold buttons at the cuffs. He speaks quickly and in bursts, often pointing a finger into the air when making a point, and sometimes pauses to jot down in a notebook slogans for his campaign as they occur to him.
He grew up in Springfield, Delaware County, and went to St. Joseph's Prep, then Georgetown University, where he studied philosophy. After that came Temple Law School, which prepared him for landlord-tenant work and real estate law. He went on to found the development company Chancellor Properties Inc., which dealt with properties mostly in Philadelphia.
He is divorced with two adult children.
After moving from Center City to Ardmore in the late 1990s, Guzzardi became known for backing conservative candidates like Sens. Rick Santorum and Pat Toomey.
Guzzardi said he became disillusioned by the politicians he financed. He declined to name names.
"I hoped by supporting good candidates we'd get good policy," he said. He said his turning point with Corbett was when the governor went back on his pledge not to raise taxes by approving the impact drilling fee and the $2 billion transportation bill that will raise gas prices. He also believes Corbett delayed the investigation into former Pennsylvania State University assistant football coach Jerry Sandusky for political gain.
Ryan Shafik, Guzzardi's friend and a campaign consultant, encouraged him to run after seeing Corbett's poll numbers. "Sure, he's a long shot, but voters should have choices," Shafik said. "Bob believes in competition, which is something all Republicans should stand for."
Guzzardi acknowledges he has more than his share of detractors, many within the Republican Party. Several past critics of Guzzardi declined to comment for this article. One longtime consultant, who spoke only on the condition he not be named, said he was surprised Guzzardi was the only Republican to challenge Corbett. He also said he believed Corbett's team was taking Guzzardi somewhat seriously, based on the court battle.
"Bob used to throw a lot of money around to influence elections, but he doesn't do so much of that anymore," he said. "He's on a crusade at this point, and I get that."
The Corbett supporters who filed the ballot challenge against Guzzardi allege that some of his signatures are ineligible, making his petition "fatally defective"; that he failed to file a statement of financial interest on the right date; and that he misrepresented himself on the petition by calling himself a lawyer. Guzzardi said he was "an inactive lawyer."
The battle has cost Guzzardi about $7,000 in legal fees, he said. He estimated the GOP may have spent more than $20,000.
"Thousands in Republican dollars," he said. "This money is supposed to be used to defeat Democrats, not Republicans!"
Lawrence Tabas, attorney for the GOP state committee, did not return a request for comment.
As a matter of principle, the court dispute has had the effect of energizing some of Guzzardi's potential supporters. At the Quakertown forum last week, several men crowded around to talk about the Republican opposition.
"It's one thing to fight a challenger, but it's another thing to make it so hard to campaign as an average person," said Ross Schriftman of Horsham. "The way it's set up now, if you're running against an incumbent, you're running against your own tax dollars. And where is that incumbent tonight? He didn't even send someone out to talk to us."