Rick Santorum’s Catholic faith is an obvious centerpiece of his campaign for the GOP presidential nomination, and it is rare for him to speak without referencing his religious beliefs. It is also rare, however, to hear him speak about his particular church, St. Catherine of Siena, which he and his family have belonged to for at least a decade. Even his 2005 manifesto on his personal faith and politics, It Takes a Family, did not mention the church. I was curious to learn more about it, so last Friday morning, I attended a 9 a.m. Mass there.

St. Catherine is a modern, low-slung brick building that sits in the affluent and hilly Washington suburb of Great Falls, Virginia. It is a notably conservative congregation—its neat grounds include a “garden for the unborn,” and the schedule offers a Latin Mass each Sunday featuring Gregorian chant sung by a professional choir.

The church claims 3,400 parishioners. Supreme Court Justice Antonin Scalia and his wife attend Mass there; at one time or another, so have Redskins quarterbacks, the head of the National Rifle Association, and former FBI director Louis Freeh. (Members of the Branch Davidians once blocked the parking lot with a protest targeted at Freeh after the Waco raid, someone familiar with St. Catherine told me.) The church also suffered brief notoriety eleven years ago when FBI agent Robert Hanssen—then a member of the congregation—was arrested for selling intelligence to Russia. Mostly, the church is home to families with school-aged children—“big families, seven-, eight- or nine-children families,” as one parishioner told me. (None of the half-a-dozen parishioners I interviewed would agree to be quoted by name, and the parish office declined interview requests.) Bishop Anton Justs of Jelgava, Latvia, who oversaw the creation of St. Catherine in 1981 as a reverend in Arlington, wrote in an email that its wealthy congregants are known for generosity. “The Catholic Church Community in Great Falls is very dedicated, intellectual and keeps strongly to Christian values … The people of the parish have been very generous in terms of contributions to the church and humanitarian aid abroad. It has been over 20 years since I left St. Catherine, but people write to me, and at Christmas time enclose a check.”

Before the GOP race began, members of the church say, Santorum attended Mass with his family nearly every day. Even with his wife, Karen, now joining him on the campaign trail, several parishioners told me that the Santorums ensure that their children attend Mass almost daily by having other congregants drive them to St. Catherine.

The day I attended, about 100 parishioners, among them many parents with small children, were gathered for a subdued, half-hour Mass without a homily. An additional group of about 30 young, red sweater-clad children, from the Catholic Montessori school on the grounds, were ushered in by teachers and a nun. Most of the parishioners who were there, many explained to me after, can be seen at Mass every day. The new Mass translation implemented at the end of last November, which most Catholics are still getting acclimated to, was already second-nature to them. After the Mass I attended, many lingered for an Exposition of the Blessed Sacrament, a ceremony in which devout parishioners kneel before the Eucharist and continuously recite a short prayer, a devotion that takes place several times a week at St. Catherine. Mary Ellen Konieczny, an assistant professor of sociology at Notre Dame who has produced comparative studies of liberal and conservative Catholic parishes, said that while Eucharistic adoration is resurging among many Catholic parishes, St. Catherine’s frequent, well-attended ceremonies, and its Latin Masses, are indications that it has a more conservative membership.