This once safely Democratic district where Murtha reigned for 35 years is now a toss-up. Longtime Murtha aide Mark Critz, 48, vows to carry on his former boss's legacy, while Republican businessman Tim Burns, 42, tries to leverage anti-Washington passion by treating his opponent as an incumbent tied to the "liberal Pelosi-Obama agenda."

The May 18 special election is the first competitive matchup of the 2010 cycle, and the stakes are high: Both parties are showering the district with high-wattage names and an overwhelming amount of paid media. The Democratic Congressional Campaign Committee has spent about $650,000 on the race and the National Republican Congressional Committee nearly $700,000.

Burns refers to Critz as "a career government bureaucrat" and contrasts that with his own background as a self-made entrepreneur who started a pharmaceutical technology company in his basement and sold it a few years ago for millions. "I worked hard, and I made it," Burns said.

"People understand that if we want real change in government, we have to elect people that aren't from government," he said. "That's what this election is about."

Critz touts his role as Murtha's protege and point man for economic development, pointing out that he helped the congressman generate money and jobs for the economically strapped district. The biography on his Web site refers largely to his years working with Murtha. He states that he intends to pick up the reins, and he adds: "I have been fighting this fight for longer than a decade."

Burns's response: Critz is no Murtha. "Murtha has big shoes to fill, and there isn't anyone in the race that can possibly fill them," Burns said. "As much as Mark would like people to believe that he can step in and do what Murtha did, people know that is simply not the case."

Meanwhile, Pennsylvania's 12th Congressional District has become a focus of national attention. Former Alaska governor Sarah Palin gave a shout-out to Burns on her Facebook page, after which he raised $80,000 online. When he appeared on Sean Hannity's Fox News Channel program, $50,000 rolled in within 24 hours. Vice President Biden visited Pittsburgh for Critz; the same week, former House speaker Newt Gingrich dropped in for Burns. And while House Speaker Nancy Pelosi was feting Critz in Washington last month, Minority Leader John A. Boehner (Ohio) was doing the same for Burns nearby.

Both candidates are about even on the fundraising ledger, with Critz receiving more than $100,000 from defense contractors that benefited from Murtha's appropriations and Burns putting $280,000 of his money into the race.

Complicating the race is the fact that the special election is on the same day as the Pennsylvania primaries -- in which Critz and Burns are also running -- for the next congressional term. On the Democratic side, Critz is opposed by Ron Mackell Jr., a lawyer, and Ryan Bucchianeri, a former Navy officer. Burns's opponent is retired Army Lt. Col. William Russell, who got 42 percent of the vote against Murtha in 2008.

Critz and Burns are heavily favored to win their respective primaries, setting the stage for an odd situation going forward: Both men will continue running for the seat -- but one of them will be in Washington serving out the remainder of Murtha's term.

Not a harsh word about Murtha crosses Burns's lips, but he assails Critz for working in an "office" that supported health-care reform and energy legislation that he says will hurt western Pennsylvania's coal industry. He even ran a paid ad charging that Critz was investigated by the House ethics committee, even though it was Murtha who was investigated. The spot never mentioned Murtha's name, but Critz launched a response ad accusing Burns of sullying Murtha's memory.

Critz's embrace of Murtha can cut both ways. Murtha's unapologetic earmarking was controversial. He was called the "King of Pork" by detractors and was investigated for directing money to defense contractors who contributed to his political campaign. Still, he was a hero at home, steering millions to a district left depressed by the collapse of the steel and coal industries.

Murtha died in February at age 77 from complications after gallbladder surgery. The oddly shaped district that zigzags around Pittsburgh was specifically carved out for him and has a 2-to-1 Democratic advantage among registered voters.

Despite its voter registration, this is a conservative area where President Obama's job approval rating is at 37 percent. Indeed, the candidates seem to be vying to be the most conservative. Both are pro-gun and antiabortion and say that they would have voted against the health-care legislation. And Burns proudly notes that last year he organized the first "tea party" rally in the area.

"When Murtha died, it scared the heck out of a lot of people. People knew we had lost a sugar daddy. What he did for the district is incalculable" said Scott Bird, a musician who described himself as a libertarian unlikely to vote for either candidate. "But people are taking a closer look now."