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.

In 2001, Reverend Franklyn McAfee, then the church’s pastor, told The Washington Times that the Santorum family had lived outside the parish boundaries set by the diocese when it joined—and therefore had to request special permission to join the parish. (A little less than one-third of St. Catherine’s members do this, he said, an unusually high number.) The church the Santorums joined was already well-known for its devout, sometimes unbridled, conservatism. In the ’90s, the National Catholic Reporter reported that a St. Catherine priest was one of a group of conservatives who overran a meeting in Sterling, Virginia, hosted by liberal Catholics supporting female priests and altar servers. He did not become violent, but he did not discourage his compatriots as they cut microphone cords and pushed some of the meeting participants to the ground. A police officer told The Washington Post, “There was more noise and carrying on than I’ve ever heard in my life, especially in a church.”

St. Catherine also has ties to Opus Dei, an extremely conservative organization that encourages members to knit their Catholic faith with policy-making. Many members of St. Catherine belong to Opus Dei, McAfee told the Times, and Opus Dei priests still regularly hear confession at St. Catherine. For his part, McAfee was an Opus Dei cooperator—a formal title that identifies someone who does not belong to Opus Dei but assists its mission.

Santorum has said he is not a member of Opus Dei, just an admirer, but he has numerous connections to the group. In 2002, he travelled to Rome with high-profile American members for the 100th birthday of Opus Dei’s founder, Josemaría Escrivá de Balaguer. (The five-day event is where Santorum first criticized John F. Kennedy’s “separation of church and state” speech, speaking to a reporter.) He has also sent two of his sons to the Heights School, a Washington, D.C. school with ties to Opus Dei.

St. Catherine is one of only about 10 sites in Virginia that offers “evenings of recollection.” These are monthly, hour-and-a-half long talks by lay people and priests belonging to Opus Dei. They are segregated by sex—St. Catherine men who attend these do so at the Reston Study Center, one town over, while women attend them at St. Catherine. Brian Finnerty, a spokesperson for Opus Dei’s national office, said that men and women are separated because an evening of recollection is “intended as a prayer time, rather than as a social time, and this gets people away from possible distractions.” He added that it also allows priests and lay speakers to tailor their messages. “For men, we could offer advice like, when you get home from work and your wife asks, ‘How was your day?’ saying ‘Fine’ as you look up from the newspaper is not an adequate response. Things like that.”