If you were thinking Constantinople you would be wrong. The New Rome is Roman Catholicism after Vatican II.
Here are a couple of data sets. One from Lawrence King and Robert Miller:
When Vatican II promulgated its Declaration on Religious Freedom (Dignitatis humanae), few expected that fifty years later the view that people do not have a right to religious liberty would become popular again. Yet this doctrine—commonly known as integralism—is experiencing a resurgence among some conservative Catholic intellectuals.
Integralism is the doctrine that (ideally, if not always in practice) the state should endorse the Catholic faith and act as the secular arm of the Church, punishing heresy among the baptized and suppressing false religious practices if they threaten Catholicism. This doctrine was taught by several nineteenth-century popes. Then, in 1965, the Second Vatican Council taught that all human beings have a right to religious freedom and that it is wrong for the state or anyone else to use force in matters of religion. . . .
From 1978 to 2013, the conservative position was dominant. Popes John Paul II and Benedict XVI insisted that Vatican II was an incremental development of the Church’s ongoing tradition, not a radical break with the past. The Catechism of the Catholic Church (1992) was an authoritative statement of this position, weaving pre-1962 and post-1962 Catholic teachings into a seamless whole. Conservative theologians deployed two powerful arguments: Against the liberals, they argued that rejecting the Church’s traditional teachings is profoundly un-Catholic. Against the traditionalists, they argued that rejecting the Church’s recent teachings, both of the Council and of the post-conciliar popes, was equally un-Catholic.
Since the election of Pope Francis in 2013, however, this conservative synthesis has been put in serious question. While not formally rejecting any of John Paul II or Benedict XVI’s teachings, Francis has scuttled many of their initiatives, removed their most ardent supporters from office while promoting several of their critics, and has taken positions on certain matters (such as gradualism in moral theology) that appear to be at odds with the views of his predecessors. As a result, some conservative theologians have concluded that Francis may be teaching serious errors.
However, once a Catholic theologian concludes that the current pope is in error, he or she opens the lid of a very deep box. If the pope has been teaching false doctrine regarding moral gradualism since 2013, then isn’t it possible that all the popes since 1965 have been teaching false doctrine regarding religious liberty? The conservatives’ strongest argument against traditionalism—“How can you call yourself Catholic if you reject the authority of the pope?”—is no longer available. As a result, some conservative Catholic thinkers have recently been reevaluating traditionalist claims on a variety of matters, including integralism.
There is a certain irony in this. Integralism extends the religious authority of the pope and bishops into the sphere of civil law, and yet the people who most adamantly defend integralism today are rarely fans of the current pope.
Or this from James Chappel, Catholic Modern:
Whatever we might think of the Church’s activism on these fronts, one thing at least is clear: it has embraced modernity. With few exceptions, Catholic thinkers and leaders take for granted that they are living in a religious plural world, and that their task is to collaborate with others in the name of the common good. They no longer call for church-state fusion or the revocation of religious freedom. They invoke, instead, human rights. They are more likely, too, to agitate for civil rights and pursue Christian-Jewish dialogue than they are to revive the Church’s long history of anti-Semitism.
Catholics have their own idea of what a just modernity should look like, of course. . . . They do not, in other words, call for an overturning of the secular order and a reinstatement of the Church as the sole guardian of public and private morality. These aspects of Catholic engagement are so familiar to us that we can sometimes forget how recent they are. A devout Catholic in 1900, anywhere in the world, would have been shocked to learn that the Church would one day support values like these. Sometime between 1900 and the present, the Church became modern. (1-2)
This is a much more serious problem than Protestants with 33,000 denominations or EIGHTY-ONE PERCENT of evangelicals voting for Trump. It means that the church, the hierarchy, the infallible magisterium, was wrong about the world, sin, and the devil for much of medieval and modern history. Roman Catholicism was not simply about grace and spiritual matters. It claimed to be the source of order in society and truth about the way humans should order their earthly affairs.
It’s like saying the Bible teaches a judgment day when the saved and lost will be separated and then realizing that Scripture teaches universal salvation. Protestants may disagree about what the Bible means, but they still regard it (the ones who believe it) to be true. Modern Roman Catholics, even before the revelations of sexual scandals for the past two decades, do not believe that popes before John XXIII were telling the truth about the church and its function in the world. And once you question the church’s function in the world, you question implicitly its teaching about salvation.