On his way to a decisive victory, Barack Obama won a majority of the nation's Catholic voters, a closely watched swing group that has sided with the winner in nine of the last 10 presidential elections.

He won despite the preaching of some conservative bishops that it would be wrong to vote for a candidate who supports abortion rights, as Obama does, and after a years-long effort by Democrats to close their party's persistent "God gap" with the Republicans among religious voters.

Fifty-four percent of Catholics voted for Obama, to 45 percent for GOP nominee John McCain, according to surveys of voters as they left their polling places. Catholics made up 27 percent of the U.S. electorate.

Pennsylvania was an anomaly, with McCain carrying Catholics 52 percent to 48 percent. A third of the state's voters were Catholic, according to the exit polls.

Catholic voters are often reflective of the national results in modern presidential elections in part because church membership ranges across so many income and racial categories, experts say. Exit polls indicate that Catholics have gone with the winner in every presidential election since 1972, with one exception - 2000, when George W. Bush lost the group to Al Gore.

This year, analysts say, the slumping economy boosted Obama among Catholic voters, just as it did among other demographic groups in the electorate.

"Economic issues just overwhelmed concerns about abortion or anything else in this election," said Alan Wolfe, director of Boston College's Boisi Center for Religion and American Public Life. "In good times, Catholics might say, 'I'm going to listen to the bishop,' but in bad times you vote your pocketbook."

Historically, Catholics tended to vote Democratic, but the party's advantage narrowed sharply during the culture wars of the last quarter century. In 2004, Catholics spurned Democrat John F. Kerry, a fellow church member, for Bush.

In response, more liberal Catholic activist groups - as well as the Obama campaign itself - sought to dilute the potency of the abortion issue by arguing Catholics should weigh equally whether a candidate agreed with the church's stands on poverty, war, the environment and human rights.

A demographic revolution within the U.S. Catholic Church also aided Obama. Nearly one-third of American Catholics are Latinos, as are a majority of church members under the age of 40. And Latinos broke overwhelmingly for Obama, because of both the economy and the latter-day GOP's perceived hostility to immigration.

Obama won 67 percent of the votes of Hispanics, an improvement of 16 percentage points over Kerry's performance in 2004.

"At some point, we don't know when, Latinos will be a majority of Catholics in the U.S., and the Republicans have just done a miserable job getting their votes - which is fascinating, because both Bush and [political strategist Karl] Rove knew it had to be done," Wolfe said.

In Pennsylvania, McCain did particularly well in the southwestern counties near Pittsburgh, places with high concentrations of Catholics who tend to register as Democrats but often vote Republican because of social issues such as abortion, pollster G. Terry Madonna said.

Populous Westmoreland County went for McCain, 58 percent to 41 percent, for instance, despite a 49,000-voter edge for the Democrats in registration.

Tom Balya, chairman of the Westmoreland County Board of Commissioners, said in an interview a few days before the election that younger Catholics were open to weighing other issues equally with abortion. Among older churchgoers, said Balya, a Democrat, "a lot of people are scared; they think you go to hell if you don't do what the bishop says."

But Obama carried heavily Catholic Lackawanna County - which includes Scranton - with 63 percent of the vote.

Bishop Joseph F. Martino of the Scranton Diocese issued a letter, which he required pastors to read to their parishioners, warning that "being 'right' on taxes, education, health care, immigration and the economy fails to make up for the error of disregarding the value of a human life." Martino continued: "It is a tragic irony that 'pro-choice' candidates have come to support homicide - the gravest injustice a society can tolerate - in the name of 'social justice.' "

The city is home to U.S. Sen. Bob Casey, son and namesake of the late former governor, both Democrats opposed to abortion rights. The senator, who enjoys overwhelming popularity in the Scranton region, strongly endorsed Obama and campaigned hard for him.

In addition, both Hillary Rodham Clinton, who won the Pennsylvania primary, and Vice President-elect Joseph R. Biden Jr. had ties to Scranton.

"Biden was born here and went to St. Paul's parish school to the third grade. . . . He was treated as a local boy during the whole campaign," said William Parente, professor of political science at the University of Scranton, a Jesuit school. "People were demoralized after Forbes magazine named Scranton one of the '10 fastest-dying cities in America,' and the city is so hungry for favorable publicity."

Indeed, reporters from around the world trooped to Scranton, which became a symbol of blue-collar scrappiness.

Martino's pronouncements "drew a negative reaction" from political leaders and voters who resented being told what to do, Parente said, citing a boycott of an annual Mass that the bishop holds to honor Catholic lawyers and judges. But there was more to it, he said: Martino has fought with the union representing Catholic school teachers and must close parishes and schools to cut costs.

"His prestige was at a low level already," said Parente, who described himself as a conservative McCain supporter who agrees with Martino on abortion.