President Donald Trump took aim at Pope Leo XIV on Saturday over the pontiff's private meeting with Chicago Mayor Brandon Johnson, calling the Democratic mayor "useless" and folding the exchange into his broader insistence that Iran must not acquire nuclear weapons. The Truth Social post reopened a public rift between the White House and the Vatican that has been simmering for months.

Trump wrote plainly, as Newsmax reported:

"Someone should explain to the Pope that the Mayor of Chicago is useless, and that Iran cannot have a Nuclear Weapon!"

The post included screenshots of Johnson's own social-media messages from his Vatican visit. Images showed the mayor handing Pope Leo XIV a miniature Chicago flag and the two holding a Cubs hat, a lighthearted touch, given that the Chicago-born pontiff is a known White Sox fan.

Johnson's 46-member delegation to Rome

Johnson had traveled to Rome leading a 46-member delegation for a multi-faith prayer service. The day before Trump's post, Johnson met privately with Pope Leo XIV at the Vatican. The mayor described the audience as "one of the most awe-inspiring and humbling experiences of my life" and said the conversation touched on social justice and the pope's reflections on slavery.

That framing alone is revealing. A city mayor whose administration has clashed repeatedly with the federal government over immigration enforcement and funding chose to fly a large delegation overseas for a meeting heavy on progressive talking points. Chicago taxpayers, already living with the consequences of Johnson's ongoing standoff with the Trump administration, might reasonably ask what the trip accomplished beyond a photo op.

Johnson responded to Trump on Saturday by accusing the president of waging a "blasphemous war in Iran." He also said Trump's belligerence was making it harder for working families to get by.

A feud months in the making

The exchange did not materialize from nothing. Trump and Pope Leo XIV have been trading public criticisms since at least April, when Trump called the pontiff "WEAK on Crime, and terrible for Foreign Policy" and urged him to "stop catering to the Radical Left." Trump also accused the pope of "endangering a lot of Catholics" by, in Trump's view, condoning Iran's pursuit of nuclear weapons.

Pope Leo XIV pushed back. He called Trump's warning that "a whole civilization will die tonight" in Iran "truly unacceptable" and said attacks on civilian infrastructure violate international law. The pope, born on Chicago's South Side in 1955, has not shied from confrontation. He told reporters in May that the Catholic Church "for years has spoken out against all nuclear weapons, so there is no doubt there."

He added that he had "no fear of the Trump administration, or speaking out loudly of the message of the Gospel."

That posture has defined much of the rare public clash between the White House and the Vatican this year. Secretary of State Marco Rubio met with Pope Leo XIV at the Vatican in May, a visit that appeared to briefly ease tensions. Saturday's post made clear any diplomatic thaw was short-lived.

The Vatican's silence, and Johnson's record

The Vatican has not publicly responded to Trump's latest remarks. That silence may be strategic, or it may simply reflect the Holy See's preference for measured diplomacy over social-media sparring.

But the underlying question Trump raised, why the pope chose to grant a private audience to Brandon Johnson, deserves a serious answer. Johnson presides over a city grappling with violent crime, fiscal strain, and a fractured relationship with federal law enforcement. His administration has positioned Chicago as a so-called sanctuary city, resisting federal immigration enforcement while simultaneously requesting federal dollars.

When Pope Leo XIV urged Americans to demand peace and spoke against nuclear weapons, he placed himself squarely in the middle of a foreign-policy debate between the White House and its critics. Hosting Johnson at the Vatican only deepened that impression, fairly or not, of a pontiff aligning with the political left on domestic American disputes.

Conservative Catholics in particular have watched this dynamic unfold with unease. A pope who speaks forcefully on nuclear disarmament and international humanitarian law commands moral authority. A pope who appears to lend that authority to a progressive mayor locked in a political fight with the sitting president risks looking like a partisan actor.

Iran, nuclear weapons, and the real stakes

Trump's post yoked two subjects together, Johnson's Vatican visit and Iran's nuclear ambitions, in a way that might seem disjointed at first glance. But the connection reflects a consistent thread in the president's public messaging: that the pope's criticisms of U.S. and Israeli military operations against Iran amount to cover for a regime seeking the world's most dangerous weapons.

The U.S.-Israeli military campaign against Iran began earlier this year. Trump has insisted throughout that preventing Iran from obtaining a nuclear weapon is a non-negotiable objective. Pope Leo XIV has framed the conflict differently, emphasizing civilian harm and calling for adherence to international law.

These are legitimate policy disagreements. But when the Vatican grants a private audience to a Democratic mayor who accuses the president of waging a "blasphemous war," the pope's office moves from moral commentary into something that looks more like political coordination, even if that is not the intent.

The Vatican's broader diplomatic posture this year has drawn scrutiny from multiple directions. Pope Leo XIV has made a series of decisions, from appointing controversial figures to lead U.S. dioceses to his public confrontations with the administration, that have placed him at odds with a significant share of American Catholic opinion.

Who benefits from this meeting?

Johnson clearly benefits. A struggling big-city mayor, battered by crime statistics and political headwinds, gets to stand beside the pope and project moral seriousness. The photos, the flag, the Cubs hat, the handshake, give Johnson a visual he can deploy against his critics. That is how politics works.

Whether the meeting benefits the Vatican is a different question. Pope Leo XIV has said he fears no government and will speak the Gospel freely. That is his right and, many believers would say, his duty. But the Gospel is not a party platform. And when the pope's calendar starts to look like a roster of the president's domestic political opponents, the moral authority that makes his voice matter begins to erode.

The Vatican has recently named a new ambassador to the United States, a move that signals ongoing engagement with Washington. Whether that diplomatic channel can bear the weight of this increasingly public feud remains to be seen.

The pattern is the point

Trump's post was blunt. It was not diplomatic. But strip away the style and the substance is hard to dismiss. A Democratic mayor who has fought the federal government on immigration, who leads a city plagued by violence, and who accuses the president of blasphemy flew a 46-person delegation to Rome, and got a private papal audience for his trouble.

Meanwhile, the Vatican has offered no public response to Trump's latest criticism. Johnson got his photo. The pope got a Cubs hat. And the people of Chicago got the bill.

When the Vatican starts picking sides in American politics, it shouldn't be surprised when American politicians start picking back.