The White House cannot stop fighting with the pope.

On Tuesday night, Vice President JD Vance — who converted to Catholicism in 2019 — accused Pope Leo XIV of not understanding the Church’s stance on war, saying it was “very, very important for the pope to be careful when he talks about matters of theology.” Later in the evening, President Donald Trump continued to berate the pope for not supporting his strikes on Iran.

In Leo, though, they’ve found a feistier opponent than they might have expected. He calmly held his ground, hit back with some jabs of his own — he called the Trump-owned platform Truth Social’s name “ironic” — and, perhaps most importantly, has brought support to bear from prominent right-leaning Catholics in the US. The top Senate Republican sounds unnerved. Trump, who is used to quickly cowing nonpartisan public figures into a more conciliatory stance, is not winning this time.

This isn’t the White House’s first run-in with a pope. Trump, and sometimes Vance, were in a long-running conflict with Pope Francis going all the way back to the 2016 Republican presidential primary, when Francis indirectly suggested that Trump “was not a Christian,” because of his focus on “building walls…and not bridges.” Back then, even Trump’s fellow GOP primary contenders, including Catholics like then-Sen. Marco Rubio, backed him up.

As a result, Trump might be surprised by how much stronger the backlash is this time. Even before he doubled down on his initial Truth Social attacks and posted a controversial (and sacrilegious) AI-generated image of himself as Jesus Christ, many of his usual allies, including conservative Catholics, were calling him out.

“The statements made by President Trump on Truth Social regarding the Pope were entirely inappropriate and disrespectful,” the Catholic Bishop Robert Barron, a member of Trump’s Religious Liberty Commission who is popular with conservative Catholics, said on X — a statement emblematic of right-leaning Catholics’ responses.

Why is the current spat so different? A lot of it has to do with Pope Leo, who starts with a much stronger base of support from American Catholics on the right. After years of sparring with Francis, Trump and Vance may find they’ve messed with the wrong pope this time.

Since assuming the papacy, Leo has shown himself adept at leveraging the optics of his office, winning over critics, and building popular appeal to strengthen his hand — all moves that Trump would surely recognize.

A lot of the goodwill on the right toward Leo has nothing to do with US politics, but with matters of faith: internal Vatican debates about doctrine and the role of the papacy. He’s made significant inroads with traditionalist and more orthodox Catholics, who were far more suspicious of Francis’ approach, and they’re more inclined to take his side as a result.

When Leo was elected pope, American Catholics, who lean more theologically and politically conservative than in other parts of the world, weren’t sure what to make of him. He wasn’t one of the so-called frontrunners, so his election shocked the world.

He was the first American-born pope, from Chicago, but like the Argentine-born Pope Francis had spent decades in Latin America, where the Church had a reputation for sometimes challenging capitalism from the left. He came from the Augustinian order, a more hermetic and austere tradition, as opposed to the more visible and liberal-leaning Jesuit order that trained Francis. Though elevated by the “liberal” Francis through the Vatican hierarchy, Leo was well-liked by both progressive, conservative, and traditionalist clerics in the Church.

Traditionalist and conservative Catholics were cautiously optimistic, and soon saw signs that Leo was rewarding their faith in him. They cheered on his restoration of the elaborate, grand, traditional symbols of the papacy, which Francis had disregarded. During his first public address, he gave a blessing in Latin — traditionalists strongly opposed the Church’s 20th-century turn away from the language — and wore the more traditional garb of the pontiff, including a red mozzetta, or short cape, (as opposed to Francis’s simple white attire).

These and other symbolic moves were a sign that “at the very least he is intentionally not following directly in the footsteps of Francis” the conservative Catholic editor-in-chief of Crisis magazine, Eric Sammons, said at the time.

And sure enough, the overtures that followed allowed a lot of traditionalists to breathe a sigh of relief. Leo was, at worst, a centrist: traditional in style and conservative in dogma, even if he carried on Francis’s tradition of Catholic social teaching. He did not immediately wade into social and cultural debates, instead prioritizing thinking on artificial intelligence, economic justice, and respect for human rights; he spoke spontaneously less often than Francis, who was known for his off-the-cuff remarks; and he did not antagonize those supporters of the Traditional Latin Mass.

He moved back to the pope’s apartments in the Apostolic Palace, which Francis had abandoned during his papacy, and picked back up old traditions, like carrying a cross through the Colosseum on Good Friday this year — something Pope John Paul II used to do. Even now, Catholic observers look for clues and signs of Leo’s theological and stylistic leanings: looking to see what vestments he wears, what regalia he bears, and who he promotes.

And perhaps most importantly, he seemed willing to reconcile and repair differences between promoters of the traditional Latin Mass and the dominant vernacular Catholic tradition that Francis promoted. Leo has gone so far as to allow discussion of the Latin Mass during gatherings of cardinals, opening up the possibility that previous restrictions might be reexamined, and called for “generous inclusion,” of its supporters, though he has reminded traditionalists not to allow their support for the Latin Mass to become a political tool.

A common knock on Francis in America was that he earned praise from secular liberals, but not new converts to counter shrinking Church attendance in the US. Leo is benefiting from the opposite trend: The American Church, in particular, is seeing a cultural revival: Young Catholics are filling pews in big city parishes and posting their experiences online. Catholicism, and its traditional aesthetics, is trendy again. Converts and baptisms are rising again, albeit slowly. Clergy and Catholic influencers are more vocal. And Leo is part of that revitalization.

It’s not just Leo’s base of support that’s coloring the reaction to his argument with Trump; it’s also the issue that’s at the center of it: the war in Iran, and the rising use of military force more broadly.

Republicans and Democrats have grown used to ignoring or explaining away certain conflicts with the Church that fall along partisan lines — immigration for Republicans, abortion for Democrats. President Joe Biden was denied communion at one South Carolina church over his support for abortion rights, which fit into a longstanding debate about how to punish pro-choice Catholic politicians.

But Leo is speaking up over an issue that is actually dividing conservative Catholics: the joint US-Israeli war in Iran. Polls show disapproval by Catholics of both Trump’s handling of the war, and the fact that the war is even happening — both departures from the double-digit margin of victory Catholic voters gave Trump in 2024, according to exit polls.

As mentioned above, popes frequently take principled stands on issues that are divisive in US politics. But they typically try to avoid getting caught up in spats with politicians and keep their critiques more generalized.

As a result, when Francis took on Trump, it was seen by many as a violation of what religion professor Stephen Prothero termed “an unspoken gentleman’s agreement in American politics” that the Catholic clergy steers clear of domestic campaign issues.

In case you need a refresher, back in 2016, Francis took time as he was wrapping up an apostolic visit to Mexico to comment on the news of the day. This was the peak of Trump’s anti-immigrant, nationalistic, “build-a-wall” upstart campaign for the Republican nomination — and just days before the make-or-break South Carolina primary — and Francis injected himself right into the middle of it.

Though he didn’t use Trump’s name, he responded to a question about the candidate by saying that “a person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian.” The comments were seen as a direct attack on the candidate.

Francis came from Argentina, where the Church played a bigger role in commenting on politics, and perhaps didn’t realize how far he was going. He had a knack for spontaneity, which sometimes led him to weighing in on issues on inopportune moments. And perhaps he was a poor fit for doing politics in a polarized time: In singling out a border wall rather than Trump’s more unique takes on moral issues, he named a position widely backed in some form by Republican politicians and even some Democrats.

Regardless of his intent, it triggered a wave of criticism from Republican Catholics: Jeb Bush and Marco Rubio sided with Trump over the pope: “We should have a strategy to secure our border…that’s not an un-Christian thing to do,” Bush said, while Rubio made the case that sovereign countries have “a right to control who comes in, when they come in and how they come in,” just like Vatican City.

And of course, Trump fired back, accusing Francis of being a Mexican “pawn” and warning that the Vatican would be “attacked by ISIS” if he were not elected president. And so kicked off the tense and standoffish relationship between the pope and Trump.

By contrast, while Leo has proven willing to respond to Trump, the “feud” this time only really began when Trump launched a lengthy personal attack against him on Truth Social.

In Francis’s case, it also didn’t help that he had already earned skepticism on the right by 2016 for his other forays into politically fraught topics, which made them less inclined to give him the benefit of the doubt. His frequent focus on the poor, on immigrants, on the persecuted, and more progressive or nuanced takes on controversial issues like homosexuality, climate change, abortion, and capitalism, all opened him up to attack and dismissal from politically conservative Catholics.

Taken together, you can see two very different popes: Francis was a trailblazer, but a controversial leader who was viewed as more antagonistic toward politicians and issues conservative American Catholics cared about. Leo has been seen as more temperate and moderate in his stances, giving him more influence when he chooses to speak up, which he has chosen to do on an issue in which he could actually project some sway.

Trump paid no obvious political price for his fights with Francis. Whether that changes with Leo, either for Trump or for his successor, he’s picked a far tougher foil this time.