CHICAGO (Reuters) - In just hours, two Catholic candidates for vice president of the United States will square off - opponents in an election year that has seen the Roman Catholic Church flex its political muscle more forcefully than ever.
Paul Ryan and Joe Biden - one a social-values conservative, the other a fierce advocate for social programs - represent the deep divisions among American Catholics, who have been an important swing vote for decades.
A Reuters/Ipsos Poll conducted last weekend reveals the divergent opinions in the Church and shows that Catholics are divided equally between Democratic President Barack Obama and Republican challenger Mitt Romney, with each winning just under 40 percent of voters. (bit.ly/Qfvay7)
As America's largest religious denomination, Catholics have long been a bellwether, picking the winner of the popular vote in every presidential election since 1972.
In the 2008 election, Obama won 54 percent of the Catholic vote. But this time, Catholics are hearing stronger advocacy on the conservative side of some issues from U.S. bishops, particularly regarding same-sex marriage and contraception. This troubles liberal Catholics, who feel Church leaders are turning too far to the right.
"There's a profound wrestling going on in the Church right now over what it means to be authentically Catholic," said John Gehring, Catholic program director for Faith in Public Life, a liberal advocacy group. "I'm worried that the Church is becoming a less friendly place for moderate and progressive Catholics who believe in the social justice mission."
The two vice presidential candidates, who will debate each starting at 9 p.m. Eastern time, embody the conflicts: Biden has been criticized for his support of abortion rights, while some nuns and bishops have objected to the budget plan Ryan put forth earlier this year because of cuts to anti-poverty programs.
Writer and former priest Robert McClory said the stance of U.S. bishops on issues such as same-sex marriage and contraception is partly to blame for the continuing exodus of non-immigrant Catholics from the Church: Lapsed Catholics have become the nation's second-largest religious group, according to the Pew Forum on Religion & Public Life. The push on sexual morality comes as the Church leadership is still recovering from the child sex abuse scandal.
"You get the feeling that the Church is a ship and that somebody amongst the crew goes down every week and drills another hole in the bottom of the boat, and eventually it's going to be a very serious situation," said McClory. "People are leaving. They're embarrassed."
Conservative voices say bishops are stressing sexual morality issues not because they don't care about poverty or immigrant rights but because church teachings are under attack.
Bishops were enraged over Obama's healthcare mandate, which required Catholic schools and hospitals to carry insurance that provides birth control, forbidden by Church doctrine, for free.
A Pew Research Centre poll in August found that Catholics who had heard of bishops' concerns over perceived restrictions on religious liberty share them - by a 56 percent to 36 percent margin. But just 22 percent of Catholics say they have heard a lot about them, and 51 percent of Catholic voters say Obama best reflects their views on issues such as abortion and gay rights.
In Illinois, Springfield Bishop Thomas Paprocki warned his flock in a letter last month of "intrinsic evils" in the Democratic platform's support of abortion and same-sex marriage and said a vote for someone who promotes such actions "places the eternal salvation of your own soul in serious jeopardy."
Archbishop John Myers of Newark, New Jersey, said in a September 14 pastoral letter that those who do not accept Church teachings on marriage should "refrain from receiving Holy Communion."
But Catholics don't always do as they're told.
Parishioners at voter registration tables after a Spanish-language mass outside St. Procopius in Chicago's Pilsen neighbourhood said their faith doesn't play a big role in their vote. "I don't mix political with the Church," said Rafael Macias, 50, who attends daily Mass and thinks he will vote for Obama.
Reuters polls show a strong independent streak among Catholics. Just 17.3 percent of Catholics think abortion should be illegal in all cases, while 16.6 percent thinks it should be legal in all cases. A total of 35.5 percent of Catholic voters favour same-sex marriage, 34.2 percent favour civil unions and 20.8 percent would allow neither.
Data on birth control is even more striking - a 2011 Guttmacher Institute study found that 98 percent of Catholic women who have had sex used artificial birth control.
Robert Jones, CEO of the Public Religion Research Institute, said the Catholic vote may shift left because of the growing proportion of U.S. Catholics who are Latino - now nearly 40 percent, according to the Catholic News Service. He noted that in 2008, Obama won the Catholic vote 54 to 45 percent - losing among white Catholics 47 percent to 52 percent but winning Latinos 72 percent to 26 percent.
Jones said Catholics don't follow bishops on all issues: "Catholics by and large say they can still be a good Catholics and disagree."
The bishops' growing focus on sexual morality issues comes as the Church celebrates the 50th anniversary of Vatican II, the Second Vatican Council, which started on October 11, 1962, and was intended, as then-Pope John XXIII put it, to open the windows of the Church and let in some fresh air.
Reforms included using the local language at Mass instead of Latin and greater participation by the laity. The changes also affected religious life, with nuns swapping habits for civilian clothes and protesting the death penalty and nuclear war.
Some now see a push back against Vatican II reforms. This year the Vatican rebuked U.S. nuns for focusing too much on social justice issues such as poverty and not enough on abortion and gay marriage.
Around one in four Americans are Catholics. The Chicago Archdiocese, the third-largest in the United States with 2.3 million members, reflects the diversity of the modern Church, both in style and in substance.
At St. John Cantius on the city's Near West Side, it still seems like the 1950s, with all the "smells and bells" - a priest chanting Latin with his back to the congregation, altar boys swinging censers and women covering their hair with lace veils.
But at St. Sabina's on the South Side, a gospel choir leads a mostly African-American congregation in hymns, and the sermon is interrupted by outbursts of "Amen!" from the pews. The sometimes controversial pastor, Father Michael Pfleger, leads protests against gun violence.
Some Catholics worship outside official venues. In the city's Boystown neighbourhood, Barbara Zeman, a woman priest whose ordination is not recognized by Church leaders, celebrates Mass for a gay and lesbian congregation.
At St. John's, attendee Dan Crout, 75, said that unless you fight to make abortion illegal, you're not Catholic.
"If you're going to consider yourself Catholic, you've got to do what the Church teaches," said Crout, who prefers Latin Mass as "more meaningful."
Laura Singer, 40, whose children go to Catholic school at a Northwest Side parish, thinks you can be a good Catholic and question authority. She supports the ordination of women, for example.
"It's our church - it's not the hierarchy's church," she said.
- To see the Reuters/Ipsos American Mosaic Polling Explorer, click here: bit.ly/Qfvay7
Reporting By Mary Wisniewski; Editing by Claudia Parsons and Ciro Scotti