PITTSBURGH — Three dozen Catholics from “Lebo,” as the Mt. Lebanon area of Pittsburgh is called, packed into Colleen Oxenreiter’s living room on a recent Friday evening. Lebo is a heavily Catholic neighborhood, and her home was the one with a giant Trump sign in the yard, by her pumpkins.

She explained the group’s mission: to reach out, in a campaign of postcards and video text messages, to Catholic Republicans who did not vote in 2020. If they vote this time, she hoped, it could be enough to win back the battleground state, and the White House.

The group had another big motivator: JD Vance, the 40-year-old Republican vice presidential nominee.

Oxenreiter recounted how a friend had recently raised concerns that former President Donald Trump was “too old.”

“I said, ‘Well, that’s why he picked Vance!’” she said. “Another eight years!”

With Election Day closing in, white Catholic voters could prove important to the GOP in Pennsylvania, a swing state often won by razor-thin margins. White Catholics tend to be reliably Republican, but in 2020, Biden, a Catholic born in Pennsylvania, capitalized on his cultural affinity with them, at least enough to narrow the partisan gap, and won the state.

In 2024, Vance is the only Catholic candidate on either ticket — a convert, economic populist and outspoken social conservative. His political profile resonates with many of these voters, who are worried about issues like education, transgender rights and the economy, in addition to abortion.

At Oxenreiter’s house party, Vance proved to be a valuable touchstone — a reassurance that no matter how much Trump may waffle on issues like abortion, Vance is one of them.

Polls paint a complicated picture of what is happening. According to recent surveys by The New York Times and Siena College, Trump holds a lead over Harris among white Catholics in Pennsylvania, 55% to 42%. Nationally, polls show that Harris now has about the same level of support among white Catholic voters as Biden did in 2020, and more than Hillary Clinton had in 2016.

If Harris maintains that level of support in Pennsylvania, it could cut into Trump’s chances of winning. Or vice versa.

“We are all in on Pennsylvania now,” said Brian Burch, the president of Catholic Vote, which organized the house party and is functioning as Trump’s Catholic mobilization campaign in Pennsylvania, Michigan, Wisconsin and Arizona.

The group regularly points out to voters that Vance is “a faithful Catholic.”

That pitch has moved Christina Costain, 48, who doesn’t love where Trump was on abortion but she said she had come to “absolutely love JD Vance.” She recently read his memoir, “Hillbilly Elegy,” and marveled at how “smooth” he was during his debate with Gov. Tim Walz of Minnesota, Harris’ running mate.

Perhaps most importantly to her, “JD Vance, he’s admitted when his mind has been changed,” she said. “He’s humble.”

She saw him in contrast to Biden, even though Biden is one of the most religiously observant presidents in modern America, and his Catholic faith is core to his entire personal and public life.

Although Biden may go to Mass, she said, she was not sure what kind of Catholic he really was. And Harris, she said, represented “a whole different vibe.”

The Trump team is leaning hard into feelings like hers. Vance is making more stops in Pennsylvania than in any other state, and Republicans are framing Democrats as anti-Catholic.

When Harris decided not to appear in person at the Alfred E. Smith Memorial Foundation Dinner, hosted by Cardinal Timothy Dolan of New York on Thursday night, the Trump campaign sent out an email blast: Her absence was “sending a powerful message to Catholics: That they aren’t welcome in her coalition.” Harris sent a video message to be played at the dinner instead, which included a Catholic character from “Saturday Night Live.”

There was also “The Doritos Ad,” as some offended voters called it. In a bizarre TikTok video, Gretchen Whitmer, the Democratic governor of Michigan, placed a tortilla chip on the tongue of a kneeling feminist podcaster. The state’s Catholic bishops accused her of mocking the Eucharist, for which the governor apologized.

“Why mock a religion?” asked Richard Lynch, who attended Oxenreiter’s house party.

But many white liberal Catholics see Harris as a true champion of their values.

Denise Murphy McGraw, national chair of Catholics Vote Common Good, is working to mobilize Catholic voters for Harris in Pennsylvania, Wisconsin and Michigan.

“She understands Catholic social justice teachings, and that’s how many of us who are multi-issue Catholic voters look at our elected officials,” McGraw said. “We want to make sure that they respect all people and lift up all lives in this country, and we see that in her.”

Her group is pushing a “Love Thy Neighbor” digital ad campaign and Catholic-to-Catholic postcard outreach.

Several independent Democratic groups like hers are rushing out their own get-out-the-vote efforts aimed at Catholic voters in battleground states. Many of those efforts are focused on nonreligious appeals to predominantly Catholic ethnic groups like Hispanics. In Pennsylvania there is an effort to turn out Catholic voters in Croatian, Ukrainian and Polish American communities who are concerned about Russian aggression in Europe.

The Catholic vote has changed greatly since the 1960s and ‘70s, when many white Catholics were reliable Democrats and John F. Kennedy became America’s first Catholic president. Many Catholics became Republicans during the Reagan era over issues like abortion, while an influx of Catholic Hispanic immigrants largely sided with the Democrats. In 2020, one in seven voters in 2020 were white Catholics.

Vance, who converted to Catholicism five years ago, represents a rising traditionalist wing of the church that has taken root in his generation. Catholic conservatives have been returning to traditionalist practices, and have grown increasingly powerful politically: Six current U.S. Supreme Court justices are Catholic, and only one of them was nominated by a Democratic president.

That rising conservative voice has been noticeable in the Trump campaign. When Trump referenced St. Michael the Archangel on social media, it caught Oxenreiter’s attention immediately. The parish where she has attended Mass all her life is named for the saint, who is said in the Bible to protect God’s people.

Oxenreiter, a critical care nurse, thought Trump’s mention of St. Michael was a sign of a personal spiritual shift following the assassination attempt in nearby Butler, Pennsylvania. She recited a prayer in her backyard, asking St. Michael to “be our defense against the wickedness and snares of the Devil.”

“I think it is tremendous,” she said of Trump’s message. “Whether he’s using it as a prop, I don’t know, but for people like us, it is very important.”

It is unclear which side will best mobilize Catholic voters.

Kimmy Mauro, a 41-year-old public high school teacher, has lived in Lebo all her life. She voted for Obama twice, but in 2016 she voted for the Libertarian candidate, Gary Johnson, because she wasn’t sold on Trump.

That changed in 2020. “When COVID hit, I lost my mind,” she said at the Lebo gathering. “I registered as a Republican immediately.”

She said that Democrats “hijacked public education and my children’s ability to learn and my ability to work.”

Everything that has happened since has cemented her political loyalties, she said. She felt vindicated when parents in the Mt. Lebanon school district won a lawsuit, after a first-grade teacher taught their children about transgender issues without informing them in advance.

“I am almost, like, a populist now,” she said. “Close the borders. Take care of our own people.”

Vance has come under heavy criticism for repeatedly spreading false claims that Haitians in Springfield, Ohio, were stealing and eating pets — smears that journalists and local officials, including Republicans, have debunked.

Voters at the gathering in Oxenreiter’s house connected with Vance’s belief that the country cannot support the current influx of immigrants. Richard Lynch and his wife, Dianne, who voted for Trump in 2016 and 2020, said that this time, they feel an urgency to become more active and mobilize Catholics like them — not only because of abortion, but also because they were worried that the current immigration process harms migrants.

“We are not doing our poor immigrants any favors by bringing them in,” said Lynch, who was worried that many immigrants could get caught up in sex trafficking.

Her husband agreed with her. Vance, he said, is “an authentic Catholic” and an “almost providential pick.”

“Pence was OK, but he is not JD Vance,” he said of the former vice president, Mike Pence.

He added, “Vance can really relate to a lot people ...” — and his wife finished his sentence: “... who are struggling.”