The Democratic campaign for governor has been a study in civil, muted tones. Three weeks before the election, the first negative ad has yet to be aired.

But the lack of rancor doesn't mean a lack of difference. In style and ideology, the four candidates have significant distinctions and occupy different points on their party's spectrum.

Joe Hoeffel, the Montgomery County commissioner, portrays himself as the true liberal in the group, while touting his ability to work across party lines.

In a troubled economy, Allegheny County Executive Dan Onorato's candidacy is rooted in the perception of progress in the Pittsburgh region, as its once lagging unemployment rate and business growth improved relative to national statistics. Amid anti-Harrisburg sentiments and legislators' prosecutions, he points to reforms in his county as evidence of the change he'd bring to the state capital.

As a former state senator and now as auditor general, Jack Wagner is a state government veteran. He says his years of experience have not molded him in the ways of the capital, instead they have taught him how to change them. As proof, he points to the audit trails of waste and mismanagement in state agencies such as the Pennsylvania Higher Education Assistance Agency and his early call for a down-sized Legislature.

State Sen. Anthony Williams represents a traditional big-city Democratic district. But his policy proposals, notably as a champion of wider school choice, confront key party orthodoxies and interest groups.

But one thing all of the Democratic contenders have in common -- along with their GOP counterparts -- is a lack of specificity on how they would deal with one of the more challenging budget environments any Pennsylvania governor has confronted. Along with a title and a nice house on the Susquehanna River, the winner will inherit serious fiscal challenges.

Gov. Ed Rendell has called the Legislature back to deal with a transportation-funding void created by the denial of federal permission to toll Interstate 80. An anticipated spike in public pension costs will represent a multi-billion dollar hit on the state budget. The state's 500 school districts will be dealing with a simultaneous pension squeeze, a situation that will almost inevitably place still more pressure on Harrisburg for local relief. Funds from the stimulus package Congress enacted last year are due to dry up. And the state Supreme Court widened the looming fiscal chasm with its decision to deny the state the ability to use $800 million in malpractice insurance proceeds for the general fund budget.

"The pension issue is between $3 [billion] to $5 billion," said Rep. Dwight Evans, the veteran chair of the House Appropriations Committee. "You have a roads, bridge and transit issue -- $1.7 billion. Federal money disappearing -- $2.6 billion; then you have the court case that just came down -- $800 million."

"The options are very limited," he added. "There is no new money."

While the perception of Mr. Hoeffel as a more liberal candidate often focuses on social issues such as abortion rights and gay marriage, he also stresses the need for an activist approach to economic issues. He offers what might be the most fundamental change for the state among all of the candidates' proposals with his call for a graduated state income tax. How much new revenue that would generate is uncertain. He has not detailed the tiers and rate levels in the new revenue structure that would replace the state's current flat-rate plan.

"Thirty-four states have a graduated income tax and we should be the 35th," he said. "It would allow the state to give a tax break for lower incomes, [but] I'm not talking about soaking the rich."

An unabashed liberal, Mr. Hoeffel says his ability to work across party lines is proven by the bipartisan alliance he has formed with Republican Jim Matthews on his county's board of commissioners, freezing out the other GOP member of the board.

Less reticent on spending than some of his rivals, Mr. Hoeffel said that the state should double its spending for transportation, including increases for repair of existing roads and bridges, more funding for transit and high-speed rail development.

All of the Democratic contenders agree with the desirability of taxing the proceeds of Marcellus shale natural gas deposits at some level. Mr. Hoeffel has been particularly outspoken on the issue, calling for rates that would produce at least $300 million in the first year of the new tax, a level his campaign projects as double the proceeds of the levy currently proposed by Mr. Rendell.

Mr. Hoeffel said he would also shift more of the state's school costs away from property taxes and toward income taxes, while raising the proportion of local school costs paid by the state from roughly 37 percent to nearly half.

Mr. Onorato says he also would gradually boost the state share of school funding. That's just one of the goals he's outlined in a series of position papers that are the most extensive among the candidates. For all of their detail, however, the policy outlines do not specify exactly how he would come up with the revenue needed to balance budgets that would include a variety of new spending initiatives.

In speeches and interviews, Mr. Onorato prefers to emphasize how he would bridge the gap from the cost side. He says that his tenure as Allegheny County executive demonstrates how he would be able to find savings in state government.

Mr. Onorato would also shrink the size of the Legislature. While he has not specified how many members would sit in the shrunken chambers, his government reform policy papers state that the shift should produce savings of at least 20 percent. Like the change in income tax structure called for by Mr. Hoeffel, the change in the Legislature's structure would require an amendment to the state constitution.

Revisiting an issue that's been a headache for him in Allegheny County, Mr. Onorato said he would change the inconsistent patchwork of county property tax assessments with a uniform statewide system. While it's an issue he'd prefer not to deal with, he says that Allegheny County's experience demonstrates that almost any county in the state is just one lawsuit away from a forced reassessment, and given that reality, a statewide approach would be preferable to a piecemeal one.

Overall, while there are differences between them on a variety of issues, the theme of Mr. Onorato's gubernatorial campaign is similar to Mr. Rendell's.

The essence of Mr. Rendell's 2002 sales pitch was, "Here's what I did to revitalize Philadelphia; I can do the same for Pennsylvania."

Mr. Onorato similarly points to the outpouring of turnaround stories Pittsburgh provided for the world media during last year's G-20 events. He says he could help spur a similar revitalization across the state.

How much credit Mr. Onorato deserves for the region's economic strides is another question. The North Side Democrat can't claim responsibility for the presence of the universities and hospitals that are new engines of the area's economy. But an ally, County Council President Rich Fitzgerald, argues that Mr. Onorato was not just along for the region's economic ride, but that he helped steer it.

"I'll give you a perfect example," Mr. Fitzgerald said. "A few years ago it was controversial with some people for Dan to support Westinghouse moving to Cranberry, out of the county. But he knew it would be good for the region, and I think it turned out better than anyone expected. He was right."

Through his career in local government, Mr. Onorato has consistently described himself as anti-abortion, although the issue of abortion rights has never been a central focus in any of his campaigns. While he says he has not changed his personal view on the contentious issue, in this race he has emphasized that he supports the state's existing, relatively strict abortion statute and said repeatedly that he would veto any efforts to change that law.

"Dan Onorato is straddling," Mr. Hoeffel said. "He's trying to convince people in the east that he is pro-choice."

Mr. Wagner, who once served on Pittsburgh City Council with Mr. Onorato, also is a traditional opponent of abortion rights.

The fact that so many Pennsylvanians have already voted for Mr. Wagner -- in his successful bids for auditor general and a failed nomination for lieutenant governor -- is evidence to him that he has a chance to win the May 18 nomination despite a big disadvantage in fundraising relative to Mr. Onorato and Mr. Williams.

Mr. Wagner and Mr. Onorato both cite a long list of endorsements from Democratic Party figures cross the state. Mr. Wagner finished first in the party's state committee balloting, but he fell short of the two-thirds majority needed for a formal endorsement. He and Mr. Onorato have both received the endorsements of several significant labor unions.

Contrasting himself with his rivals, he said, "No one knows this government in and out the way I do."

Mr. Williams, the Philadelphia state senator, was a surprise late entry in the Democratic contest, and to voters unfamiliar with his record, or with Philadelphia politics, some of his policy proposals may be a surprise.

His signature issue is a call for greatly expanded school choice. Saying that the current system of public education is failing, Mr. Williams would funnel school aid through parents, so that they could choose traditional public schools, magnet or charter schools or faith-based institutions. The senator insists he is not an enemy of traditional public education.

"Nobody in this race has voted for more money for education that I have," he said. But his position is sharply at odds with the views of some traditional Democratic constituencies, such as teachers unions.

Mr. Williams' school choice position has won him six-figure support from investment bankers interested in the issue, making him the only Democrat besides Mr. Onorato who has aired significant television advertising in the race. Given those large donors, it is not surprising that, unlike some other candidates, he does not support contribution limits. Instead, he would fight the perception of pay-to-play politics with a ban on no-bid state contracts for contributors who donate more than $1,000.

Seeking money for property tax relief, Mr. Williams would ask the Legislature to legalize keno and other forms of gaming in bars and taverns.

With a base in the largest concentration of Democratic power in the state, Mr. Williams has been endorsed by Philadelphia Mayor Michael Nutter; Rep. Bob Brady, the city's powerful Democratic chairman; and state Rep. Dwight Evans, another outspoken proponent of broader choice in public education.

Mr. Williams is the only African-American candidate in the primary, but his school policy proposals and his startling fundraising performance have attracted more attention than his race.

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