Marine Le Pen has a complicated relationship with Catholicism. The twice divorced leader of the National Front, France’s far-right nationalist party, has spoken in favor of women’s abortion rights and won gay and lesbian support. She has doubts about Pope Francis, and during the first round of the French election, she criticized her conservative Catholic opponent Francois Fillon for “the opportunistic use of that faith to defend a certain political line.” This, she said, undermines the principles of French secularism, or laïcité, and is “contrary to our values.”

And yet Le Pen heads a party (despite having temporarily stepped down as National Front leader to focus on the elections) whose mascot is the Catholic saint Joan of Arc; this religious figure stands in contrast to Marianne, the secular symbol of the French republic who represents liberty and reason. Le Pen claims she has “a strong faith,” presumably referring to the Catholicism with which she was raised, and feels “fortunate in that I have never doubted it.” And when she defines French identity, she points to the Church at its core: “The principles we fight for are engraved in our national motto: liberty, equality, fraternity,” she declared at a rally. “That stems from the principles of secularization resulting from a Christian heritage.”

Le Pen’s success in the recent round of voting for France’s next president, which will go to a run-off on Sunday, marks a resurgence of nationalist populism in the country. While religion isn’t necessarily driving French policy debates or voting behavior, Le Pen’s campaign illustrates how nominal religious values can be used as an argument for closed borders and stronger national identity.

The National Front has always had a mixed religious identity. In the early days of the party, which was founded by Marine Le Pen’s father, Jean-Marie Le Pen, “fundamentalist Catholics … were a moderately strong tendency within the party,” said Rogers Brubaker, a sociologist at the University of California, Los Angeles. But “there were also … anti-Christian paganists” in the party, he added, and “those who were indifferent to religion and much more concerned about immigration.”

For his part, Jean-Marie is known as a Roman Catholic. He was the one who chose Joan of Arc as the party’s mascot. (This year, during the National Front’s annual May Day pilgrimage to a statue of the French warrior in Paris, he memorably screamed, “Help, Jeanne D’Arc!” as he laid a wreath at her feet.) In 2012, his granddaughter Marion Maréchal-Le Pen became the youngest representative to the French parliament in modern history, and she has represented the more traditionalist Catholic wing in the National Front.

And yet, Marine has made clear the divisions between her party and the Catholic Church. In an interview with the Catholic magazine La Croix, she said she is “angry with the Church, because I think that it interferes in everything except what it should really be concerned with.” The pope’s call for European leaders to take in migrants and refugees “asks that states go against the interests of their own people,” she argued. “I don’t get involved with what the pope should say to his followers. I don’t think religions should tell the French people how to vote.”

Le Pen does invoke religion, however, when she’s trying to declare who the French are and are not—specifically when she’s talking about Islam, Brubaker said. “This is a Christianism—not a substantive Christianity,” he argued. “It’s a secularized Christianity as culture … It’s a matter of belonging rather than believing.” He thinks Le Pen’s brand of Christianity as a form of identity has emerged in response to widespread Muslim immigration into the country over the last 10 or 15 years: In her view, “We are Christians,” Brubaker said, “precisely because they are Muslims. Otherwise, we are not Christian in any substantive sense.”

In 2002, Jean-Marie Le Pen made it to the run-off in the French election, shocking many. He earned an explicit rebuke from the French council of bishops: The clergy urged voters to reject the National Front candidate largely because he had denied or underplayed the significance of the Holocaust. At the time, the archbishop of Paris was Jean-Marie Lustiger, whose Polish Jewish parents had been deported to concentration camps by the Nazis during World War II.

The bishops have “quite conspicuously not done so this time,” said Brubaker. “That reflects what’s happened in the intervening time: This very successful move of Marine Le Pen to so-called ‘de-demonize’ her party.” She kicked her father out of the National Front and has tried to get rid of the party’s reputation for anti-Semitism (only somewhat successfully). And she has attracted more religious voters, Brubaker said. “Survey data show that over the last decade or so, she’s been able to increase her Catholic vote, probably because the party has changed its profile.”

“She wants to build a Europe of peoples. It’s a complete turnaround.”

Catholic voters have traditionally had more favorable attitudes toward the National Front than other French people: 2016 data from Pew Research Center shows that slightly less than one-third of the group are partial to the party. But while Catholic voters have arguably been going through something of a renaissance in France, Marine can hardly take credit for it. Several years ago, large turnout for Catholic-led protests against same-sex marriage surprised commentators, who weren’t expecting to see such widespread support for the socially conservative position. And in the early days of this round of the French election, it looked like the traditionalist Fillon might revive France’s “zombie Catholics,” as one columnist in Foreign Policy put it.

After Fillon did poorly in April, in part due to a corruption scandal surrounding his family, Catholics were left politically homeless. But some may find themselves drawn to the National Front this weekend, despite Le Pen’s tepid embrace of their values.

Tamir Bar-On, a professor at Tec de Monterrey in Mexico, argues that Le Pen’s “religious” appeal is actually nationalism. Her political platform contains 144 proposals, and religion is “nowhere to be seen, practically, in all of that,” Bar-On said. In fact, the National Front argues that “the Republic does not recognize any community” or religious particularism, Bar-On said—proposal #95 of its platform calls for the promotion of laïcité as a means of protecting cohesive French identity.

The issues that seem to matter, Bar-On said, are “terrorism, French values and French identity, jobs and unemployment, social security, [and] immigration.” In other words, Le Pen’s candidacy is all about defining and promoting what it means to be French. While some Catholics may dislike her rejection of the world of porous borders Pope Francis has called for, others may be attracted to her defense of national identity. Many French Catholics “see French national identity as threatened by the forces of militant Islam and progressivism,” the writer Pascal-Emmanuel Gobry recently argued in America magazine. “Traditional French national identity seems a much more hospitable milieu for Catholicism than either of the alternatives.”

John Bowen, an anthropologist at Washington University in St. Louis, offered a third theory: Religion doesn’t play much of a role at all in this election. While Fillon championed some of the family issues that are important to Catholics, Bowen said, the run-off “features two people who aren’t thought of as being highly invested in Catholic issues.” He sees Le Pen’s reaction to Islam in terms that are less religious than economic and cultural: “It’s about elites, it’s about not being listened to, it’s about immigration, it’s about job issues,” he said. “The new people” in France whom she is angry about “just happen to be Muslims.”

Le Pen may make general claims about the “Christian heritage” of French identity, but her actual claim is that religion itself is not particularly important. “She wants to build a Europe of peoples,” Bowen said. “It’s a complete turnaround from the idea of religious toleration and acceptance of all peoples who are responsible French citizens.” For Le Pen, identity trumps theology, and nation trumps Church. France’s “zombie Catholics” must now decide whether they agree.