Bill Roth, president of the Catholic Democrats political action committee, said the American Roman Catholic Church is split between "believers in social theology" who are most concerned about poverty, health care and war, and "those with a firm adherence to pelvic theology," who are driven to the polls by issues such as abortion and same-sex marriages.
"Just like the American people, Catholics are divided, but not along party lines," Roth said.
Compared with previous elections, Democrats have become more organized in recruiting Catholic voters, said Patrick Whelan, head of Catholic Democrats, a Boston-based organization.
"It's dramatically different this time," said Whelan, who was co-director of Catholics for Kerry in 2004. He pointed outside of formal campaign efforts to the activities of groups such as the Matthew 25 network, a political action committee that promotes Christian values, and grass-root groups that have sprung up on social networking Web sites like Facebook.
Reese, the Georgetown professor, isn't sure it's enough. The Obama campaign is not doing enough to highlight the candidate's Catholic ties, failing to remind voters that his community work two decades ago in Chicago was funded by the Catholic Church, he said. Or that when he was younger, Obama attended a Catholic school in Indonesia.
"The problem is the white Catholics look at Obama and he doesn't look like them, so he has to connect with them on a gut level," said Reese. "He has all the programs to appeal to these people - health care, jobs, economy. ... They really don't get it as far as I can see, on how to appeal to Catholic voters."
Biden's modest upbringing, his inspiring personal tale of hard luck and lifelong relationship with the church was supposed to resonate with many of those voters.
"I'm as much a cultural Catholic as I am a theological Catholic," he wrote in his 2007 memoir, Promises to Keep. "My idea of self, of family, of community, of the wider world comes straight from my religion. It's not as much the Bible, the Beatitudes, the Ten Commandments, the sacraments, or the prayers I learned. It's the culture."
Still, despite these efforts, Catholic voters in recent weeks seem to be breaking toward the Republican ticket.
Social issues of concern to many religious voters had taken a back seat this year until McCain selected Palin, the governor of Alaska and a staunch abortion opponent, as his running mate. As the public learned biographical details, such as how Palin continued a pregnancy after learning the baby would be born with Down syndrome, the abortion issue has grown in prominence.
