On Wednesday, Francis unleashed another aspect of his complex public persona: The disappointed prophet who excoriates world powers for mistreating the poor and marginalized.
Celebrating Mass in Ciudad Juarez, a city just across the border from the United States, Francis delivered a stinging critique of leaders on both sides of the fence, calling the "forced migration" of thousands of Central Americans a "human tragedy" and "humanitarian crisis."
"Being faced with so many legal vacuums," the Pope said during his homily before a congregation of more than 200,000 people, "they get caught up in a web that ensnares and always destroys the poorest."
"Injustice is radicalized in the young," the Pope continued. "They are 'cannon fodder,' persecuted and threatened when they try to flee the spiral of violence and the hell of drugs."
The Bible readings at the Mass, which are tied to the church calendar, told the story of Jonah, another angry prophet. It was the kind of coincidence that a man of Francis' faith might consider the work of a watchful God. The Bible passages set up the Pope to blister injustices in Mexico and indifference in the United States, casting both countries as modern-day Ninevehs
'No more death! No more exploitation!'
"Go and tell them that injustice has infected their way of seeing the world," the Pope said, describing Jonah's mission to rouse the city of Nineveh from the morass of moral decay. "Go and help them to understand that by the way they treat each other, ordering and organizing themselves, they are only creating death and destruction, suffering and oppression."
In case the message was lost on his audience, the Pope drove the point home:
"Let us together ask our God for the gift of conversion, the gift of tears, let us ask him to give us open hearts like the Ninevites, open to his call heard in the suffering faces of countless men and women. No more death! No more exploitation!"
Before the Mass, Francis prayed and blessed a makeshift memorial to migrants who have tried to cross into the United States. He then blessed a group of about 400 people across the river in El Paso. Included among these "Francis VIPs"
were families seeking asylum in the United States, according to El Paso Bishop Mark Seitz.
It was a grand geopolitical gesture from the Pope's political playbook, mirroring his prayer at the wall separating Palestinian territories and Israel in 2014. It also thrust Francis into the polarized debates over immigration in both the United States and Mexico.
Vatican responds to Trump's charge
Even before the Pope arrived in Mexico, GOP front-runner Donald Trump called Francis
a "very political person" and suggested he was a tool of the Mexican government.
The Vatican scoffed at the latter charge but pleaded guilty to the former.
"The Pope, with his moral and spiritual ministry, may have a political impact. That is clear to the whole world by now, " Vatican spokesman, the Rev. Federico Lombardi, said Tuesday night when asked about Trump's accusations.
Look at Francis' role in encouraging renewed relations between the United States and Cuba, for example, the spokesman said, adding that the Pope has also encouraged Europeans to care for the refugees at their borders.
Trump, arguing that immigrants are bringing drugs and crime across the southern U.S. border, has pledged to build a big wall to keep them out.
Bishop Daniel Flores, who has been traveling with Francis during his five-day trip in Mexico, said the central themes of the Pope's sermon and papacy are the same: a call to conversion. "No one is exempt from this; it is addressed to everyone: government leaders, politicians, bishops, clergy, young people, families, prisoners, business leaders."
It is unclear, though, whether American Catholics or politicians will heed the Pope's call. GOP candidates Marco Rubio and Jeb Bush, who are Catholic, have openly disagreed with Francis on the environment and may be anxious to align themselves with his stance on immigration, too.
Meanwhile, half of Catholics in the United States say they agree with Francis on that issue, according to a survey conducted by the Public Religion Research Institute. But a majority of conservative Catholics (54%) say that Trump, whose signature issue is buttressing the border between the United States and Mexico, would make a "good or great" president, a Pew poll found.
Sister Norma Pimentel, executive director of Catholic Charities of the Rio Grande Valley, was one of thousands of Catholics who gathered in El Paso to watch the Pope bless the memorial and celebrate Mass in Juarez.
"I hope that every single politician takes note of this trip and thinks of it before they take action," Pimentel said. "I hope they consider the dignity of all people."
An exuberant welcome
While the Pope's Mass on the border was the political highpoint of his trip to Mexico, for the most part, Francis' speeches were notably apolitical. He condemned corruption and drug cartels, but the deeply unpopular Mexican government escaped with hardly a scratch.
As he did in the United States and elsewhere, the Pope encouraged his huge audiences to adopt more merciful approaches to the poor, elderly and the young, but offered no policy prescriptions.
Still, his agenda spoke volumes. He went to the heart of the cartel's dark territory in Morelia, Michoacan, and told the young crowd that Jesus wants them to be disciples, not "hitmen." And in Chiapas, in the country's far south, where many people have indigenous heritage, he said the world needs their culture and asked for forgiveness for those who had contaminated their lands.
There, and nearly everywhere Francis went, the crowds' response approached rapturous. It was "an overwhelming outpouring of spontaneous affection," said Flores.
Many Mexicans cried in his presence; others cheered like a soccer crowd, "Viva el Papa!" and "You can see it, you can feel it, the Pope is here!" At times the crowd was too exuberant, as when Francis was pulled down on top of a boy in a wheelchair.
At the end of the Mass in Juarez on Wednesday, the Pope thanked Mexicans for opening their doors and their lives to him.
"At times I felt like weeping to see so much hope in a people who are suffering so much," Francis said.