Vatican City (CNN) - Program notes: Tune in to the new CNN Original Series, "Pope: The Most Powerful Man in History," Sundays at 10 p.m. ET/PT.
In the beginning, there were signs and wonder.
Signs that Jorge Bergoglio would be different, which led 1.2 billion Catholics to wonder: What kind of Pope would this obscure archbishop from Argentina turn out to be?
When the Vatican sent him a first-class ticket to 2013's papal conclave, he traded it in for coach. While most cardinals took limos to Vatican City, he walked or hopped the bus. After his election as pope, he chose a modest room in the Vatican's guest quarters instead of a frescoed suite in the Apostolic Palace.
But the strongest indication of his values came with his choice of a papal name.
Just before the white smoke billowed from the Sistine Chapel chimney, Brazilian Cardinal Claudio Hummes hugged his fellow South American and said, "Don't forget the poor."
The words made an obvious impression, for moments later Bergoglio informed the conclave that he would take the name Francis. It was in honor of St. Francis of Assisi, he later explained. The choice brought gasps and applause. No pontiff had ever paid such a tribute to the rich, 12th century man who gave his wealth to the poor and became a beggar for Christ.
But the name was just the beginning. Five years later, Pope Francis is firmly among the most liberal, global and politically relevant Holy Fathers in modern history.
And for some Catholics, that's become a problem.
He rails against the evils of capitalist greed and climate change. In a dig at Donald Trump, he said that those who build walls to keep out immigrants are "not Christian," and even flew Muslim Syrian refugees to safety on his papal plane.
When asked about the existence of gay priests he shrugged, "who am I to judge?"
He's opened discussions about allowing married priests in the Amazon, permitted divorced and remarried Catholics to take Communion and said that God redeems "even the atheists."
As a result, a recent Pew survey of US Catholics found that 55% of Republican Catholics say Pope Francis is "too liberal," a number that's more than doubled since 2015.
While 84% of American Catholics have a "favorable" view and nine in 10 find him "compassionate" and "humble," a growing number of conservatives in the US and Europe worry that he may be a borderline heretic, a naive South American socialist or both.
"Conservatives, by nature, are pro-Pope. So you want the pope to be right," says Thomas D. Williams, a former priest and the Rome bureau chief for the right-wing website Breitbart News.
"And then a liberal one comes along ... it's really a new thing for Catholics."
Now, Williams says, "there is kind of an agglomeration" of conservatives "with different concerns that are joined in the fact that they think that the Pope might be a danger ... And I think that there was a critical moment when benefit of the doubt ran out and some conservatives just said this is going in a bad direction. It's time to resist."
That resistance is unique in its visibility. Out of deference or fear, papal criticism has historically come in whispers, but bookstore shelves now hold new titles like "Lost Shepherd," "The Dictator Pope" and "The Political Pope: How Pope Francis is Delighting the Left and Abandoning Conservatives."
"I now understand how liberals in the church felt under the pontificates of John Paul II and Benedict," says Benjamin Harnwell, director of the Institute for Human Dignity, a religious right-wing think tank. "I never got it before. I thought they were just dissenters, but they really didn't feel as if they were truly part of the church, and that the Vatican didn't involve or want them. Well, the pendulum has swung the other way."
As Harnwell strolls his new headquarters -- an ancient monastery in the hills outside Rome that holds magnificent paintings of Christian persecution and the bones of St. Boniface -- he explains his belief that The Vatican is a house divided.
There are those like Pope Francis, who believe the church should be more like a field hospital, attending to the wounded -- regardless of faith or denomination -- while creating a more Christ-like society on earth.
And then there is his camp, which sees the Catholic Church as a supernatural organization, here to enforce the strict rules of heavenly entry.
In a cold, abandoned sanctuary, Harnwell twists in his chair and sighs when asked for his thoughts about the Pope: "We're basically out in the doghouse right now."
Like many here, he admits he never saw this turn of events coming five years ago.
After Vatican corruption and sex scandals, conventional wisdom says the cardinals picked an outsider to clean house. When it comes to church hierarchy, he has not disappointed.
Still, there is one glaring criticism of Pope Francis that both liberals and conservatives can agree on: his defense of Bishop Juan Barros, a Chilean cleric who is accused covering up the crimes of a pedophile priest.
After strong backlash, Pope Francis sent a Vatican sex crimes expert to Chile to investigate, and spokeswoman Paloma Garcia Ovejero insists that the pontiff does not have a blind spot when it comes to abuse by members of the clergy.
"Pope Francis wants to know the truth," she says. "We cannot change the past, but we can try to change the future and to protect today's children and future children. To have zero tolerance, prosecute the guilty and put victims first. Pope Francis is following these guidelines like a train and he will never stop till he finishes with this shame."
Both supporters and detractors note that much the way a president stacks the courts, this Pope is rearranging the clergy -- from cardinals to nuns -- in his own image. He is 81 years old, but the reign of "Francis the Reformer" could continue beyond the next conclave.
"Early on he promised a short papacy," said Williams, the Breitbart voice in Rome, who shrugs away the chance to handicap the longevity of Pope Francis.
"He works very hard ... he takes a lot of trips. He's a man whose health has not been great. But honestly, he seems invigorated by being Pope. And maybe this will last a lot longer than anybody thought."