Tom Corbett, Pennsylvania’s unassuming attorney general, is leading his Democrat challenger, Dan Onorato, by an increasingly daunting margin in the polls. Rasmussen has him up 13 points, with a commanding 50-37 percent lead. That’s a three-point gain in just two weeks in the same poll.

Onorato, meanwhile, is working the margins, hoping to win the affection of some of the 17 precent that are still undecided. (Those are PPP’s figures. Rasmussen has only 9 percent undecided.)

At this important transition point, as both campaigns tamp down in preparation for the final two months leading up to election day, a tax war has has broken out.

Corbett took to the air this week with his first ad since the primary, reminding voters of his pledge to oppose tax increases. Onorato has spent the week in me-too mode, complaining that he, too, has promised not to raise income or sales taxes in his first term.

But when is a tax not a tax? When it’s called a “fee,” and neither man has explicitly ruled out fee increases – like the kind term-limited Gov. Ed Rendell has proposed — despite their read-my-lips pledge on taxes for the state’s general fund.

“It’s a muddled field at best where both gentleman stand on the tax issue,” said Terry Madonna, Director of the Franklin & Marshall College Poll, in an interview with Battle ‘10.

“Let’s understand what matters to voters,” said Madonna. “Both of these men have ruled out the big taxes on things like income and sales. The only other taxes are on things like gasoline, cigarettes, and niche taxes that fall on users of a particular service or product. And voters have never been particularly outraged about those.”

Other taxes, like those on extraction of natural gas from the Marcellus shale formation, also remain in play. Nearly $12 million in revenue is already generated annually from drilling permits alone.

“The difference in philosophy could not be greater,” said Kevin Harley, spokesman for the Corbett campaign, in speaking with Battle ‘10. “Tom Corbett is a fiscal conservative, while Dan Onorato’s role model is Ed Rendell.”

Ed Rendell, in his eighth year as governor (and before that mayor of Philadelphia), has been criticized for legalizing slot machine gambling, failing to pass six of eight annual budgets on time, and for creating a fiscal environment increasingly dependent on federal stimulus funds that will dry up once he leaves office.

Harley said Corbett is opposed to both tax and fee increases. The Grover Norquist-backed Americans for Tax Reform pledge that Corbett signed on Feb. 10 covers opposition to tax increases, but does not include any explicit rejection of accompanying fee increases.

When asked whether Corbett would consider a theoretical no-fee-increase pledge, Harley said, “Corbett would consider a pledge on fee increases, but I’m not sure there is such a pledge out there.”

Nathan Benefield, Director of Policy Research at the Harrisburg-based Commonwealth Foundation, had harsher words for the would-be governor. “Corbett’s recent dancing around whether fees would violate his ‘no new taxes’ pledge should concern voters, Benefield told Battle ‘10.

“Certainly there are many government fees which truly function as user fees — like the cost of copies at the library — but many ‘fees’ are just taxes with a different name, taking more money from residents to use for wasteful government programs, [like] the slew of proposed vehicle and driver fees to fund a transportation system filled with corruption and in dire need of spending reforms.”

The Onorato campaign did not immediately return a request for comment. In a conference call last week with reporters, though, Onorato affirmed his pledge not to increase sales or income taxes.

But, as the Harrisburg Patriot-News reported, Onorato said “he could be open to taxing a few of those items [not currently subject to sales tax] individually down the road.” These potential future increases could include taxes on coal, basic television, candy and gum, flags, firewood, newspapers, magazines, and malt beverages.

“These candidates understand that tax hikes right now are lethal,” said Madonna. “Onorato’s problem is that he wants to replace a Democrat [in Rendell] whose job performance has plummeted and who has, almost weekly, called for tax hikes.”