The Slatest

Pope: Trump “Is Not Christian.” Trump: Tell It to ISIS. 

The popemobile rolls through Ciudad Juárez on Wednesday. 

Yuri Cortez/AFP/Getty Images

Donald Trump is never one to shy away from a public spat. But Megyn Kelly’s got nothing on his latest sparring partner.

During a midair press conference on his way back from Rome after a six-day visit to Mexico, Pope Francis was asked about Trump and said, “A person who thinks only about building walls, wherever they may be, and not building bridges, is not Christian.” 

The pope has been outspoken in his support for the rights of migrants and refugees and his trip to Mexico included a visit to the U.S.-Mexico border in Ciudad Juárez, where he gave mass for more than 200,000 people and laid flowers on a memorial for those who have died trying to cross the border.

Asked if he would urge Catholics not to vote for Trump, Francis demurred, but repeated, “I say only that this man is not Christian if he has said things like that. We must see if he said things in that way and in this I give the benefit of the doubt.”

Trump, campaigning in South Carolina, fired back almost immediately, calling Francis’ comments “disgraceful,” and saying that no religious leader “should have the right to question another man’s religion or faith.” This seems to be a principled stance he developed since last week when he questioned Ted Cruz’s faith:

He continued: “If and when the Vatican is attacked by ISIS, which as everyone knows is ISIS’s ultimate trophy, I can promise you that the Pope would have only wished and prayed that Donald Trump would have been president.” (It’s true that ISIS leader Abu Bakr al-Baghdadi has told followers they will “conquer Rome,” but he says a lot of things and the group likely has more pressing issues for the time being.)

Trump’s rival Jeb Bush, a convert to Catholicism, was asked about the exchange and said that Trump’s Christianity is “between he and his creator.” But he also scoffed at Trump’s warnings about ISIS, saying, “The Swiss guard is probably taking pretty good care of the Pope.” Bush also said he supports building a wall “where it’s appropriate” to prevent illegal immigration but voiced his respect for the Pope.

Thursday’s sniping follows several days of back-and-forth between Trump and the Vatican. The day before the pope arrived in Mexico, the candidate told Fox Business that the pontiff is a “very political person” who doesn’t understand “the danger of the open border that we have with Mexico.” He also suggested that the Mexican government had talked the pope into speaking out on immigration. A Vatican spokesman called these comments “very strange,” noting that Francis’ concern for migrants and refugees is global and that he has spoken about these issues in many countries, not just Mexico.

This certainly isn’t the first time that the Catholic Church has inserted itself into a U.S. presidential race. In 2004, for instance, a prominent Vatican cardinal urged U.S. priests to deny communion to Catholic politicians, like then Democratic candidate John Kerry, who support abortion rights. But this is a very different Vatican and a very different U.S. election.

Read more Slate coverage of the GOP primary.