NEW YORK — In one corner: Pope Francis, who insists on a merciful Catholic Church open to everyone, a “field hospital” ready to bind up the wounds of a suffering humanity. In the other corner: a small but vocal minority that has set itself against the Pontiff and his reforms.

A showdown between the two is under way.

The unofficial leader of the opposition is US Cardinal Raymond Burke, one of the church’s legal experts and a figure whose style and approach harken back to the church of a different era and whose views closely align with those in its traditionalist wing.

Francis, while maintaining he upholds the church’s doctrine and principles, has tried to move the church on from some of those customs he sees as hampering its mission.

Those who oppose Francis say they are deeply concerned about his openness to giving communion to divorced and remarried Catholics, along with his pastoral welcome to LGBTQ people. They don’t like his focus on migrants and the climate crisis, and they want a pope instead who lays down the law and presents doctrine in black-and-white terms.

This Pope preaches for a humbler church, one focused on service and which seeks to bring the Christian message into the world.

While the attacks on him are likely to have stung, Francis has frequently turned the other cheek, going so far as to say he does not seek to crack down on opponents; he’s also appointed to Vatican departments leaders who held different views than his own.

Now, though, in the 11th year of his papacy, the Pope is taking more assertive measures to tackle some of the opposition he’s been facing, which is centered in the US — where American politics also may be in play — and in certain Roman circles.

With his 87th birthday Sunday and as he battles health issues, he doesn’t have time to waste.

Francis has decided Burke, an opponent of his for years, will lose some of his privileges, reportedly including a subsidy for his 4,488-square-foot apartment and monthly stipend.

It follows the Pope’s move last month to remove from his leadership post Texan Bishop Joseph Strickland, who had accused Francis of undermining the central teachings of the church, including on politically charged issues like abortion and same sex marriage.

Supporters of Burke and Strickland have said Francis is a “dictator” pope, clamping down on dissent, while others suggest the Pope is punishing his critics.

While the attacks have no obvious precedent in recent history, Francis has allowed them to continue, often ignoring them. He’s also aware sometimes silence is the best response and reform often meets resistance.

“Francis told me that he was taking away the apartment and salary of Cardinal Burke because he was using these privileges ‘against the church,’” Austen Ivereigh, a papal biographer, told CNN. Ivereigh met the Pope on Nov. 27.

“Clearly, his patience had finally run out,” Ivereigh explained. “For so long, Cardinal Burke had been calling into question Francis’ authority and his teaching. This would be shocking in any organization, but it is particularly shocking in the Catholic Church, given the special role the papacy has in upholding unity.”

Francis is happy to be criticized but pointed out cardinals make a specific oath of obedience to the pope and his successors, Ivereigh said.

In 2018, Burke told a group of Catholics in Rome there are circumstances when it would be acceptable to disobey the pope. The crowd reportedly clapped and cheered. This would have been unthinkable under previous pontificates, in which loyalty to the papacy was placed at a premium by conservative Catholics.

The traditionalist cardinal from Wisconsin has said the signature reform effort initiated by Francis — the synod — “forgets the divine nature of the church.”

It’s likely to have been the final straw for the Pope.

“A pope of Cardinal Burke’s temperament would not have tolerated such dissent for one day, let alone 10 years,” said Dawn Eden Goldstein, a theologian and canon lawyer based in Washington, DC.

The Strickland case, meanwhile, is distinct from Burke’s. A bishop in the Catholic Church is not a “branch manager” for the Pope and has a degree of autonomy.

Strickland was removed after a Vatican inquiry into his leadership found it was not “feasible” for him to continue at the helm of the Diocese of Tyler, east of Dallas.

Strickland also took the extraordinary step of calling Francis’ legitimacy into question, something that goes against the communion bishops must keep with popes.

Burke, on the other hand, remains a voting cardinal. He was the equivalent of a direct employee of the Pope in Rome, and his criticism of Francis is more judiciously worded than Strickland’s has been.

Cardinals leading departments in the Roman Curia, the church’s central administration, are given grace-and-favor apartments and paid up to $5,900 a month. But Burke no longer has a job in the church’s central administration, and the decision about his apartment comes as the Vatican seeks to tackle a financial shortfall by ensuring it is getting market rates on its properties.

The cardinal had served as the prefect of the church’s supreme court equivalent (where he remains an adviser) and was later patron of the Order of Malta. In this ancient Catholic chivalric group, he became embroiled in the order’s public dispute with the Pope.

The row centered on condom distribution, with Burke pushing for the removal of one member of the order and claiming to have the backing of the Pope. Documents released by Wikileaks suggested the cardinal did not have Francis’ authority to do so.

CNN has reached out to Strickland for comment, and Burke declined to comment.

Opposition to Francis is also tied to secular politics. Burke described himself as “very happy” with the election of President Donald Trump and has joined other US bishops in calling for President Joe Biden, a Catholic, to be refused communion for his support for abortion laws.

In 2004, Burke, then a bishop, announced he would not give communion to presidential candidate John Kerry for similar reasons. While Francis has spoken out strongly against abortion, he does not support refusing Biden communion.

Strickland has described the US president as “evil” and sent a video message to a rally seeking to overturn the 2020 election result. The politicized church rhetoric is likely to heat up as the US heads into an election year.

“MAGA (Make America Great Again) politics and MAGA Catholics overlap in many ways, especially in their culture war approach to everything,” David Gibson, director of the Center on Religion and Culture at Fordham University, told CNN.

“It is all about generating anger and defining yourself as what you are against as what you are for.”

Both supporters of Trump and Burke fear they are losing their once-privileged place in the church and society, so they portray the past as a “golden age,” Gibson said.

The Pope has described some of his opponents in the US as “backwardists,” saying they have replaced faith with ideology. Gibson added: “Cardinal Burke and his ilk can justify anything they say or do against the Pope – they (believe they) are key to saving the church from the Pope.”

Goldstein, the DC theologian and canon lawyer, has met the cardinal on a number of occasions and says there “are people and organizations that would like to see Burke’s vision of the church become the dominant one because it would make the church more useful to political interests.”

The cardinal wrote the foreword to a book criticizing the synod, which was supported by a group opposed to Catholic teaching on questions such as care for the poor, the environment, indigenous populations and migrants, she pointed out.

The cardinal seeks to create an aura around himself that gives the “illusion of a return to a former era” and Francis has been tolerant of attacks, Goldstein said.

Yet, as Goldstein said, such dissent is novel in recent years and would have been unimaginable in the last few papacies.

Others point out that removing the cardinal’s privileges could have unintended consequences and turn Burke into a “martyr” for the cause.

Massimo Faggioli, a church historian at Villanova University, told CNN it might make Burke, who is supported by donors from the US and is likely to find other accommodation in Rome, a kind of national cardinal.

This would be similar to the “crown cardinals” of the early modern era, who were nominated or funded by a European Catholic monarch, he said.

The reported decision on Burke could also influence a future papal election by alienating some cardinal electors who would want to opt for a candidate who governs differently from Francis.

The Pope is likely aware of the risks – and willing to run them, given his mission. Last September, Francis created 21 new cardinals, including three fellow Argentinean and two other Latin American, 10 Europeans, three African, two Asian and just one from the US, Robert Francis Prevost, who was born in Chicago but has carried out most of his pastoral ministry in Peru.

Central to the Pope’s vision is pivoting the church to what is essential to the Christian faith. The Brazilian theologian Leonardo Boff recently tweeted a photo of Burke wearing the “cappa magna” ceremonial cape, a train of watered red silk.

Boff, who previously served for many years as a Franciscan priest, is a key proponent of liberation theology, a Latin American movement that places special emphasis on serving the poor.

He clashed with Vatican authorities in the 1980s but always maintained healthy relationships with Brazilian bishops and has a good relationship with Pope Francis. “Francis is one of us,” Boff said in a 2016 interview with German newspaper Kölner Stadt-Anzeigr.

“My brothers and sisters, conservative Christians, tell me,” he wrote when he posted the photo: “what does this cardinal with all his pomp have to do with the Jesus who was born in a manger and died on a cross?” — CNN