In an outspoken, iconoclastic career spanning three decades and two parties, Barbara Hafer has earned plenty of headlines in campaigns, mostly successful, for an array of state and local offices.

"It's always fun when I'm in there," she said Wednesday in the wake of her unexpected decision to withdraw from the scramble to succeed Rep. John P. Murtha.

But on Wednesday, as has been the case repeatedly in recent years, Ms. Hafer drew more attention for the races she didn't enter -- for governor, U.S. Senate and now twice for Congress.

Ms. Hafer said that she decided to drop her candidacy due to a combination of potential problems with her nominating petitions and her recognition of the strength of her leading Democratic opponent, former Murtha aide Mark Critz. Ms. Hafer said that in the course of the hasty campaign she mounted after Mr. Murtha's Feb. 8 death, she had been forced to rush to collect the 1,000 signatures required for her candidacy. She said ended up submitting papers with 1,058, a slim margin of error in a process where names are regularly disallowed for flaws such as signatures from voters who do not reside in the district or are not registered in the candidate's party.

Ms. Hafer's decision leaves four Democrats in the primary race: Mr. Critz, Ryan Bucchianeri, a Washington County businessman; Ronald "Ron" Mackell Jr., a lawyer and Johnstown native; and Ed Cernic, the Cambria County controller.

In her brief campaign for the seat, Ms. Hafer had repeatedly assailed Mr. Critz, the party choice and perceived frontrunner, arguing that his ties to the pork barrel politics of his former boss would make him vulnerable to Republican attacks in the fall.

But Mr. Critz turned the other cheek in a statement welcoming her withdrawal. "She would have been a formidable challenger and I respect her decision," Mr. Critz said.

Ms. Hafer has made a career of bucking party establishments. In 1988 she upset Democrat Don Bailey in the first of her two terms as auditor general. Two years later, as the GOP struggled to find a challenger to the popular former Gov. Robert P. Casey, they turned to Ms. Hafer. As "the sacrificial lamb," in her words, she was clobbered by a margin of more than two-to-one. But she went on to win another term as auditor general, and then two terms as state treasurer.

Those would be her last statewide victories before a series of terminated candidacies. Before the 2002 election, her bid for the GOP nomination for governor was cut short as the Republican establishment lined up solidly behind her Allegheny County rival, Michael Fisher, who lost to Gov. Ed Rendell before being appointed to the federal bench.

Ms. Hafer subsequently endorsed Mr. Rendell, and then switched her registration to Democratic.

"The governor's race was something I couldn't control," she recalled Wednesday. "That was the final straw with me, after giving so much service."

In 2005, she was eyeing a challenge the next year to former Sen. Rick Santorum, before Mr. Rendell and other state and national Democratic leaders urged her to step aside, clearing the way for the son of her former opponent, as Bob Casey Jr. ousted the conservative in a 2006 landslide. Later in the same election cycle, the Democratic Congressional Campaign Committee courted her for a challenge to Rep. Tim Murphy in the 18th Congressional District. Ms. Hafer never formally declared her candidacy for the seat, but she toyed with the idea of running for weeks, and her decision against the bid was a disappointment to the DCCC.

Ms. Hafer said one of the deterring factors for her that year was that while she still owned a home in the district, she had by then moved to Indiana County.

She said Wednesday that she hadn't had time to consider the possibility of any future runs for office.

"This was a really unique opportunity," she said. "I don't know what the future will bring, but you really have to be prepared when you run. You almost have to run a year ahead. That's what I've always done in the past."

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.