It's a potentially massive voting bloc that defies easy analysis.

Yet Pennsylvania's approximately 3.8 million Catholics are on the receiving end of major outreach efforts from Sen. Hillary Rodham Clinton and Sen. Barack Obama, as the candidates look for an edge in the April 22 primary. So far, Mrs. Clinton has outpaced Mr. Obama among Catholics in primary contests across the country, and polls give her a significant edge here.

Still, many local Catholics argue that it's impossible to put them in a box, and they draw from a broad range of church teachings on moral issues and the value of life when deciding how to vote.

"I just don't think that there is a consensus out there in the Catholic community, any more than there is in the broader community," said Lois Campbell, vice president of the Pittsburgh Interfaith Impact Network. "The people I know and connect with in the church are a pretty even mix."

For Ms. Campbell, a registered Democrat who hasn't selected a candidate, the top concerns are the war in Iraq and the impact of a weakening economy.

"I really believe that it's never a good idea to vote for or against a candidate based on a single issue," she said.

Ms. Campbell is a local field organizer for Catholics in Alliance for the Common Good, a nonpartisan organization based in Washington, D.C., that is polling Pennsylvania Catholics, both Republicans and Democrats, to find out their top concerns.

The alliance is planning an assembly on faith and politics in Scranton on April 17 and a much larger national gathering in Philadelphia in July.

"We are called as Catholics not to simply follow partisan political agendas, but to draw wisdom and guidance from the fullness of Catholic social teaching with its focus on the dignity of the human person, justice and the common good," said Alexia Kelley, the alliance's executive director.

Both campaigns are appealing to that world view and trumpeting the support of prominent Catholics to make further inroads in the community.

"In primary after primary, we have witnessed support for Hillary from thousands of lay Catholics," Kathleen Kennedy Townsend and Robert F. Kennedy Jr. write in a letter that is being circulated via electronic and regular mail. "Political pundits have offered various explanations for this phenomenon, but we believe the answer lies with the recognition by Catholic voters of her long commitment to and work on behalf of others."

Burns Strider, director of faith outreach for Mrs. Clinton, said the candidate's backing among Catholics was "broad and deep" and the campaign would be scouring databases and conducting door-to-door canvassing to identify supporters.

Mr. Obama has been touting the endorsement of Sen. Bob Casey, Pennsylvania's freshman senator and son of the late Gov. Bob Casey Sr., who won handily among Catholics and spawned a generation of voters -- "Casey Democrats" -- who were willing to buck the party on social issues, such as abortion.

Mrs. Clinton, a Methodist, and Mr. Obama, a member of the United Church of Christ, both back abortion rights. Yet some anti-abortion Democrats say that issue won't deter many Catholics, especially those who attend church infrequently or place more emphasis on bread-and-butter issues like access to health care and good jobs.

"It's on her conscience if it's what she believes," Dennis Johnson, the organist at St. Mary of Mercy Church, Downtown, said of Mrs. Clinton's abortion stance after a midday Mass this week.

But Mr. Johnson, 61, is still a Clinton supporter.

"We've had great woman leaders all over the world, and the U.S. has never had a chance to have a woman," he said.

An informal survey of four parishioners at the church, including Mr. Johnson, found four different viewpoints on the 2008 race: one Obama supporter, one Clinton supporter, one Republican and one independent.

Only Democrats can vote in the party's primary.

"I think the Catholic vote tends to be all over the place," said Rep. Mike Doyle, D-Forest Hills, who is remaining neutral in the primary. "We're much more a product of the socioeconomic fabric of our communities."

A poll released by Quinnipiac University this week showed that 46 percent of all Pennsylvania voters rated the economy as their most important issue.

It's the top concern for Joyce Rothermel, executive director of Greater Pittsburgh Community Food Bank, which has seen a drop in smaller donations from individuals. Meanwhile, rising food and gas prices are cutting into the organization's $9 million budget.

The food bank is making do with more money from major donors. But government funding also has declined steadily at time when the U.S. is spending billions of dollars monthly on the war in Iraq.

"You think of all you could do with that money," said Ms. Rothermel, a Democrat.

In February, she went to a meeting at Sharpsburg's Madonna of Jerusalem Church on "Faithful Citizenship," a document that U.S. bishops approved last year to give Catholic voters moral guidance in the 2008 election.

"We talk about the formation of conscience around the issues," said Father James Wehner, who has conducted about 10 sessions on the bishops' advice at parishes throughout the Pittsburgh diocese. (The next one will be held April 8 at St. Jude the Apostle in Wilmerding.)

"What we don't do is tell people how to vote."

Yet, during the meetings, some people say they want the bishops to tell them how to vote. Others say Faithful Citizenship is a biased document.

But Father Wehner steers the discussions, which have attracted about 500 people, away from specific candidates.

"I think many people may vote simply because they're a Democrat, simply because they're a Republican, or simply because their union told them to vote this way," he said. "That's a minimalist approach to civic responsibility."

For many Catholics, abortion trumps all other issues. And the issue has led some Western Pennsylvania voters to become Republicans despite the region's deep roots in Democratic politics.

Helen Cindrich, of North Versailles, president of People Concerned for the Unborn Child, left the Democratic Party in the 1970s because of her opposition to abortion. But she said Catholic Democrats who plan to vote in the primary should still consider moral issues, such as providing care for the sick and poor, when making their decision.

"You have to pick the best possible candidate, even when it's a tough call," she said.