Both parties are fighting for the votes of Catholics, who make up about a quarter of the national electorate and even more in several key states.

By DAVID D. KIRKPATRICK

SCRANTON, Pennsylvania - Until recently, Matthew Figured, a Sunday school teacher at the Holy Rosary Roman Catholic Church here, could not decide which candidate to vote for in the presidential election.
He had watched progressive Catholics work with the Democratic Party over the last four years to remind the faithful of the party’s support for Catholic teaching on the Iraq war, immigration, health care and even reducing abortion rates.
But then his local bishop barred Senator Joseph R. Biden Jr. of Delaware, the Democratic vice-presidential nominee, from receiving communion in the area because of his support for abortion rights.
Finally, bishops around the country scolded another prominent Catholic Democrat, House Speaker Nancy Pelosi of California, for publicly contradicting the church’s teachings on abortion, some discouraging parishioners from voting for politicians who hold such views.
Now Mr. Figured thinks he will vote for the Republican candidate, Senator John McCain of Arizona. “People should straighten out their religious beliefs before they start making political decisions,” Mr. Figured, 22, said on his way into Sunday Mass.
A struggle within the church over how Catholic voters should think about abortion is once again flaring up. Political partisans are preparing an all-out battle for the support of practicing Catholics in towns like Scranton that could sway the vote in states where the race is tight.
The theological dispute is playing out in diocesan newspapers and weekly homilies, while the campaigns scramble to set up phone banks of nuns and private meetings with influential bishops.
The Catholic vote, once reliably Democratic, has been split nearly in half in recent presidential races. Evenly divided in a New York Times-CBS News poll over the summer, Catholics make up about a quarter of the national electorate and about a third in the hotly contested states of Michigan, Missouri, Ohio and Pennsylvania.
“Whoever wins the Catholic vote will generally win our state and, most of the time, the nation,” said G. Terry Madonna, a political scientist at Franklin & Marshall College in Lancaster, Pennsylvania.
And Scranton is a focus of special attention this year. Senator Barack Obama of Illinois, who generally underperformed with Catholics in the Democratic primary, lost the surrounding Lackawanna County by a ratio of three-to-one in the Democratic primary to Senator Hillary Rodham Clinton of New York.
Many Clinton supporters here said they were planning to vote for Mr. Obama, some saying they sided with their labor unions instead of the church and others repeating liberal arguments about church doctrine broader than abortion.
“I think that one of the teachings of God is to take care of the less fortunate,” said Susan Tighe, a lawyer.
But more said they leaned toward Mr. McCain, citing both his experience and his opposition to abortion.
After the 2004 election, progressive Catholics started to organize and appeared to win some victories. Last fall, the bishops’ conference revised its official statement on voting priorities to explicitly allow Catholics to vote for a candidate who supports abortion rights if they do so for other reasons. The statement appeared to leave room for Democrats to argue that social programs were an effective way to reduce abortion rates, an idea the party recently incorporated into its platform.
The debate is already playing out in the letters section of Scranton’s newspaper, said Jean Harris, a political scientist at the Jesuit-run University of Scranton. “It is a running debate between Catholics saying ‘abortion is the only issue’ and others saying ‘you have to look at the whole teaching of the church,’ ” she said.