Anna Banahasky and Sue Hoover were having pie at the Spring House Restaurant in North Strabane when the conversation of comfort food gave way to less calming talk of transition.

The two women, both Democrats, will soon vote for a congressman to replace John P. Murtha, the colossus whose pork-barrel legerdemain kept the 12th District's economy churning, if not flourishing.

"I want somebody younger in there, who'll do a better job," said Ms. Banahasky.

"For me it's going to be taxes," chipped in Ms. Hoover. The recently passed health care bill, they say, leaves them uncomfortable.

In a district that has long belonged to a Democrat from Johnstown even as it drifted away from the national Democratic message, Ms. Banahasky offered three words the Republicans want to hear: "I just might."

She just might, as in, vote a Republican into Congress.

The candidates are Tim Burns, 42, a conservative Republican, tea party organizer and self-made millionaire, and Mark Critz, 48, a conservative Democrat who has spent much of his career on the byways of the sprawling 12th District, working economic development projects funded through Mr. Murtha's seat on the House Appropriations Committee.

"The common theme is people who love America and want to ensure that their children and grandchildren have a strong opportunity in this country," said Mr. Burns.

"At the end of the day, they're voting values," said Mr. Critz.

The 12th District, a 2-to-1 Democratic assemblage of Rust Belt factory towns and rural sprawl stretching from the West Virginia border to the Allegheny mountaintops, has trended conservative for the past decade. While returning Mr. Murtha to office during that time, its voters barely supported John Kerry in 2004 and narrowly rejected Barack Obama two years ago. It is a place in which people still consider themselves New Deal Democrats or Hubert Humphrey Democrats.

That ambivalence about the national Democratic agenda could presage the same sort of epiphany that landed earlier this year when voters in Massachusetts elected Republican Scott Brown to fill the seat of the late Democratic icon Edward M. Kennedy. This sort of political hammer blow -- at once practical and symbolic -- is what GOP leaders are hoping for in Mr. Burns.

The prospect has Rob Gleason, chairman of the state's Republican Party and lifelong resident of the 12th, aching with desire.

"I have to win this. The whole country's looking to me. The whole state's looking to me. If Scott Brown can do it, why not Rob Gleason?" he said.

Mr. Gleason and other party leaders all but hand-picked Mr. Burns during a special nominating vote in March. The move left supporters of another candidate, Bill Russell, a paleoconservative Army veteran who came close to upending Mr. Murtha two years ago, bitterly disappointed if not simply bitter.

Mr. Russell is staying in the May 18 Republican nominating primary, which will be held simultaneously with the special election to fill the remaining eight months of Mr. Murtha's unexpired term. On the Democratic side, two relative unknowns -- attorney Ron Mackell and Washington County businessman Ryan Bucchianeri -- have raised little money and less attention.

The simultaneous vote holds open the slim but intriguing possibility that voters could elect Mr. Critz or Mr. Burns while nominating one of their challengers for the November election. Political experts see it as unlikely.

"It's very unlikely for a voter to split his ticket within a party," said Joseph DiSarro, head of the political science department at Washington and Jefferson College.

Mr. Russell, who has yet to post high in the polls, has nonetheless swamped his rivals in fundraising, with more than $730,000 raised in the last quarter but most of it rolled back into further fundraising and direct mail. By comparison, Mr. Burns raised $225,000 -- much of it from a personal loan to his campaign. Mr. Critz raised $376,000.

The frantic pace at which both sides are now fighting for the seat is evident not so much in fundraising -- to date, the intake has been modest because of the short span of the campaign. But the National Republican Congressional Committee and the Democratic Congressional Campaign Committee have both placed large media buys across the district.

The Republicans post a photo of the party's official hobgoblin, House Speaker Nancy Pelosi, and say Mr. Critz supports her and the much-maligned health reform bill. Mr. Critz insists he did not and does not support the bill.

"They want to paint me as this liberal, and I'm not," said Mr. Critz. "I said early in my campaign that I wouldn't have supported the health bill."

Mr. Burns is doing all he can to reinforce perceptions of Mr. Critz as a liberal and to tie him to Ms. Pelosi. At a fundraiser last week in Somerset County, he told attendees that while "this isn't my dream job," going to Congress offers the fulfillment of one wish: "Telling Nancy Pelosi to her face what I actually think of her."

The line brought sharp applause. But the Republican ad also brought a sharp response.

The Democrats made media buys last week depicting Mr. Burns as a tax-hike wannabe, citing his endorsement of the so-called "Fair Tax," which calls for replacing income taxes with a flat, 23 percent national sales tax. Mr. Burns has stated that he does not think such a plan is feasible at this time.

Democrats also accuse Mr. Burns of selling his software company, something he did, causing its jobs to leave the area. Mr. Burns insists the purchaser expanded operations at the industrial park outside Pittsburgh International Airport, though he ducks the issue of whether any jobs were lost in the shift.

With each man making a plausible argument that the television ads don't properly explain them, they, in turn, lay out agendas that in many ways are surprisingly similar and diverge only in emphasis.

Mr. Burns is running as a hardline fiscal conservative who talks about spending cuts everywhere but defense.

"We are way beyond deficit reduction," said Mr. Burns. "We have to start talking about deficit elimination."

Where Mr. Critz's late boss, Mr. Murtha, was king of the earmarks, directing billions in defense dollars to his district, Mr. Burns at once criticizes such deals and yet won't flat-out declare that the defense spending in the 12th District has been a problem.

"Appropriating money for defense is not wasteful spending. There's no shame in being a strong advocate for your district," he said.

Mr. Critz, in turn, regards the earmark process as entirely defensible, but unlikely to be much of an issue.

"It doesn't matter if it's Burns, it doesn't matter if it's me. Neither one of us is going to be the chairman of the defense appropriations subcommittee," he said.

The similarities, too, suggest the potential for either man to co-opt the other's message if the race turns on "value" issues. Both agree on gun control -- they're against it. Both agree on abortion -- they oppose it. They're both Catholic and each can lay claim to two homes: Mr. Critz was born in Irwin but lives in Johnstown; Mr. Burns was born in Johnstown but lives in Eighty Four. Both attended the same college -- Indiana University of Pennsylvania.

The race could turn on stylistic matters with the memory of John Murtha occasionally looming like Banquo's ghost.

In the Cambria-Somerset-Indiana corridor, long a part of the 12th District, the Murtha legacy is still lauded, especially in Johnstown, which derived its economic lifeblood from earmarks Mr. Murtha steered to defense contractors with plants in the city.

But Cambria, once the cornerstone of the 12th, long ago lost that pride of place. The bulk of the district's voters now stretch through southern Westmoreland, Fayette, Washington and Greene, and all of those counties are thought lush hunting ground for conservative Democrats willing to switch allegiances now that Mr. Murtha is gone and his seat on Appropriations buried with him.

While not conceding Cambria, Mr. Burns knows he must do well in vote-rich Westmoreland County, where Republicans have been winning state offices in the past few years.

"It's absolutely critical," Mr. Burns said.

But even there, where the national Democratic message meets with little enthusiasm, the idea of a congressman bringing jobs, by hook or by crook, is still potent. Mr. Critz, who knows much of that county by working earmarked public works projects with local towns, intends to compete heavily there.

Bryan McCallen, a 32-year-old construction worker from Derry Township, said that if jobs become the issue, it could help Mr. Critz, a man he likes if only because in that area, Mr. Murtha was seen more as a local pol than a national Democrat.

"That's how politicians bring in jobs and stuff. They bring in earmarks and pork barrel," said Mr. McCallen.

That, notes Dr. DiSarro, is what makes the election's potential to be nationalized by the two parties, such a potential pivot for Mr. Burns.

Thirty-six years ago, it was Mr. Murtha who benefited from an influx of national attention. He was the first congressman elected following the famous Saturday Night Massacre, when a Watergate-logged Richard Nixon fired his special prosecutor and set in motion the impeachment that followed later that year.

In a remark that could have been uttered in 1974, much less this past Friday, Dr. DiSarro summed up the race in the 12th:

"This should tell us something about the future of the administration."

Washington correspondent Daniel Malloy writes the "Pittsburgh On The Potomac" blog exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.