Marco Rubio’s faith is becoming a major story in the Republican presidential campaign, especially as the candidates prepare for the first caucus in Iowa next week. A video showing the Florida senator’s response to a question from an atheist last week went viral and mainstream publications are taking note.

This week POLITICO’s cover story explored the long and winding road of Rubio’s faith journey and how it could affect his chances for the Republican nomination:

Rubio, who has never lost an election, is manifestly ambitious, a baby-faced, step-skipping climber ever since he got on the city commission of the tiny municipality of West Miami when he was 26 years old. His religious life, on the other hand, stands apart. He has been a seeker and a searcher. He has struggled always, he has said, to balance what he wants in this life with what he wants from the next. But Rubio wants to be saved more than he wants to be president. And the former could cost him the latter.

The Rubio family attends two churches in Miami: one is a nondenominational Protestant church. The other is a Catholic parish. POLITICO’s reporter found that people in both congregations weren’t surprised by Rubio’s double-dipping:

In both churches I talked to people who had no problem that Rubio and his family attend services at both churches. “I wouldn’t say it’s too unusual,” Matt Gutierrez told me at Christ Fellowship. “A lot of us do that,” Toni Mamert told me at St. Louis Catholic Church. “We practice our Catholic faith, but we can go for the word of God and study the word of God at another denomination.”

Culturally and spiritually, evangelicals and Catholics in Rubio’s generation are more comfortable seeing each other as allies, as we’ve seen with ecumenical movements such as The Manhattan Declaration and in our own work at The Stream. But there are still those evangelicals who are suspicious of Catholics — and POLITICO found them in Iowa:

“I would not say anything derogatory about Catholics, but Marco Rubio is very open that he is part of the Catholic Church,” said Brown, the Marion Avenue Baptist pastor, who has spearheaded the effort to get pastors in all 99 of Iowa’s counties to endorse Cruz. “When you say you’re doctrinally aligned with the Catholic Church, it really is contrary to what most evangelicals in Iowa believe.”

Royce Phillips, the pastor of Tabernacle Baptist Church in Coralville, told me Rubio’s answer in Des Moines surprised him and impressed him — “he seemed genuine,” he said — but that he remains uncommitted. “I’d prefer a Baptist president,” he explained.

When Rubio is asked why he attends both the evangelical church and the Catholic parish, he responds: “Because they preach from the same Bible.”

As for the implicit question of whether or not that’s even OK? “I think one of the amazing things that’s happened over the last 15 years, for a lot of different reasons, is some of the denominational divisions in America have fallen away as more and more believers recognize that we are all facing a common challenge.”

In Rubio’s own words, his time at an evangelical Southern Baptist church strengthened his faith and helped him to understand his Catholicism better, now from the foundation of the Bible:

“I think too many Catholics don’t fully understand their faith, and the result is I didn’t learn about the Catholic Church until I went to a non-Catholic church,” he said, “and became infused in the Bible and became infused in the written word of God, and then and only then did the liturgy of the church start even making sense. I started to begin to understand the richness of the church.”

It’s a story that many evangelicals who have become Catholics, and vice versa, understand. Whether or not that translates into votes at primary time is another question.