Democratic presidential candidate Joe Biden speaks at Morris Brown AME Church in Charleston, S.C., in July. A Catholic priest in South Carolina denied communion to Biden last weekend, a decision made over the former vice president’s stance on abortion. Meg Kinnard/Associated Press, file

COLUMBIA, S.C. — A Roman Catholic priest’s denial of communion to Joe Biden in South Carolina last weekend illustrates the fine line presidential candidates must walk as they talk about their faiths: balancing religious values with a campaign that asks them to choose a side in polarizing moral debates.

The awkward moment for Biden came during a weekend campaign swing through South Carolina, a pivotal firewall in his hopes to claim the Democratic presidential nomination. The former vice president on Sunday visited St. Anthony Catholic Church in Florence, a midsize city in the state’s largely rural northeast. As he frequently does on the trail, Biden – a lifelong Catholic – made a stop at a local parish, attending services without the press before stopping at other churches with reporters.

But the Rev. Robert Morey at St. Anthony opted not to serve communion to Biden. The priest said in a statement to media outlets that his decision was based on Biden’s support of abortion rights, something Morey said the church cannot condone by way of sacrament.

The episode recalled the divisive debate that erupted in 2004, when then-senator and future Democratic presidential nominee John Kerry grappled with public warnings from several Catholic officials that abortion-rights supporters should not receive communion. As Biden joins other candidates in making his faith a key element of his pitch to 2020 voters, Morey’s communion denial raises questions about whether other Democrats might face similar tests of their ability to balance personal beliefs and their public stances on key issues.

Biden’s campaign has declined to comment on the situation. Asked about it Tuesday on MSNBC, the former longtime Delaware senator shifted to an overall discussion of his views on faith.

“I practice my faith,” Biden told the network. “But I’ve never let my religious beliefs, which I accept based on church doctrine … impose that view on other people.”

The denial prompted Faithful America, a liberal-leaning grassroots Christian group, to launch an online petition calling on South Carolina’s Catholic bishop to direct Morey to apologize to Biden and direct other priests in the state not to deny communion based on politics.

“Jesus said, ‘Take, eat – when you do this, do this in remembrance of me.’ He didn’t say, ‘Take, eat – but only if you agree with certain American political positions,'” the Rev. Nathan Empsall, an Episcopalian priest and Faithful America’s campaigns director, said Tuesday, expressing displeasure about past threats to deny communion to Democratic politicians including Kerry and Virginia Sen. Tim Kaine.

What remains unclear is whether other priests might take a cue from Morey when it comes to Biden’s stance on abortion, which the Catholic Church counts as a sin. Pope Francis has asserted church opposition to abortion, equating it to “hiring a hit man” to resolve a problem, but also suggested that communion should not be withheld from practicing Catholics based on a specific belief.

“The Eucharist … is not a prize for the perfect but a powerful medicine and nourishment for the weak,” Francis wrote in 2013.

John Carr, director of the Initiative on Catholic Social Thought and Public Life at Georgetown University, said that “it’s a big loss for our faith and for our church, either way, when the Eucharist becomes a source of division instead of unity.”

“In my view, denying communion to people for their public stances is bad theology, bad pastoral practice and bad politics,” added Carr, who spent two decades as an adviser to the U.S. Conference of Catholic Bishops.

In addition to Kerry, Kaine faced a potential denial of communion in 2016 when he served as the Democrats’ vice presidential nominee. Biden is the first Democratic presidential hopeful in 2020 to face pressure from his faith about his politics, but some of his rivals have staked out clear positions on issues that divide voters in their faiths. Vermont Sen. Bernie Sanders, who’s Jewish, has called for conditioning U.S. aid to Israel, for example, while South Bend, Indiana, Mayor Pete Buttigieg, an Episcopalian, and Massachusetts Sen. Elizabeth Warren, a United Methodist, have come out against threatening the tax status of churches that oppose same-sex marriage.

Biden’s communion denial is also particularly impactful because of his campaign’s heavy investment in South Carolina, including the hiring of the Rev. Michael McClain as its faith outreach director earlier this year. (Buttigieg’s campaign, and that of New Jersey Sen. Cory Booker, also have hired dedicated faith advisers.)

McClain, pastor of historic Liberty Hill Missionary Baptist Church in Catawba, said his “task and duty” is to make Biden’s introductions to faith leaders across the state, a job McClain said is made easier by Biden’s own deeply held personal faith.

“It’s not hard to present him to the faith community because they know him,” McClain said.