Democrats who vote in the 18th Congressional District primary will be confronted by the same old question: Who in this field can run a strong campaign and defeat Republican Tim Murphy, who first won the seat in 2002?

In a district where Democrats now account for nearly 54 percent of the registered voters, with Republicans at a pale 38 percent, the answer, amazingly, has been nobody. Despite a voting record that's been loyal to the Bush administration, Mr. Murphy has been able to resist ouster in a district that includes southern Allegheny County and parts of Beaver, Washington and Westmoreland counties.

With President Bush's popularity sagging, opposition to the Iraq war growing and now an economy tumbling into recession, Democrats smell big gains to be made in November in U.S. House districts, and at least three are wondering why not in Pennsylvania's 18th.

Steve O'Donnell, Beth Hafer and Brien Wall are vying for the party nomination on April 22 and share similar views on major issues. They want to shift the military's focus away from the war in Iraq and toward the battle in Afghanistan. They not only want to extend health care to the uninsured but also make it available without crippling deductibles and exorbitant premiums. They want to save Social Security without resorting to privatization.

While their positions may sound alike, Mr. O'Donnell is the one with a sufficient grasp of the details to go toe-to-toe with the incumbent in the general election.

Ms. Hafer, 35, of Mt. Lebanon stands apart from her opponents due to gender and the name made famous by her mother Barbara, the former state treasurer, auditor general and Allegheny County commissioner. A former teacher at Winchester-Thurston School and Moon Area Middle School and a former employee of Legg Mason Real Estate Services, the candidate is now a vice president for Hafer & Associates, a consultant firm founded by her mother to improve the efficiency of business and government.

Mr. Wall, 59, of Upper St. Clair is employed by Massachusetts Mutual Life Insurance Co. and has been a Democratic committeeman for 26 years. He has been active in the community through Allegheny County Health Choice, Easter Seals, St. Francis Health Foundation and his Catholic parish.

Mr. O'Donnell, 62, of Monroeville has had a career in helping special-needs adults and children. He was a counselor at the state prison in Pittsburgh, then served for 15 years as executive director of the Westmoreland County Chapter of the Pennsylvania Association of Retarded Citizens. He and his wife ran Nisar, Inc., a company that provides services to people with behavioral health problems, then he helped form ROAM Investments Inc., a holding company where he was managing partner.

He is articulate on the issues, with positions that show a broad knowledge and thorough understanding of the nation's challenges. He has the endorsement of the Allegheny County Democratic Committee, which will be helpful in the fall campaign against a three-term incumbent. As an unsuccessful challenger in a state legislative race (against Rep. Joseph Markosek in 2006), he also knows how hard an underdog must work against a well-known opponent.

Even though Mr. Murphy will work hard to distance himself from the fallout of the Bush administration, the Democrats will have an uphill fight against him. Steve O'Donnell is the best shot for the party from this primary field and he has earned the Post-Gazette endorsement.