This month, Francis makes his first trip to the US at a time when his progressive allies are heralding him as a revolutionary, a man who only last week broadened the power of priests to forgive women who commit what Catholic teachings call the "mortal sin" of abortion.
Yet, as he upends church convention, Francis is also grappling with a conservative backlash. In more than a dozen interviews, including with seven senior church officials, insiders say the change has left the hierarchy polarised over the direction of the church. The conservative rebellion is taking on many guises - in public comments but also in the rising popularity of conservative Catholic websites promoting Francis dissenters, and books and promotional materials backed by conservative clerics seeking to counter the liberal trend.
In his recent comments, Burke was also merely stating fact. Despite the vast powers of the Pope, church doctrine serves as a kind of constitution. And for liberal reformers, the bruising theological pushback by conservatives is complicating efforts to translate the Pope's transformative style into tangible changes.
Rather than stake out clear stances, the Pope is more subtly, often implicitly, backing liberal church leaders who are pressing for radical change, while dramatically opening the parameters of the debate over how far reforms can go. For instance, during the opening of a meeting of senior bishops last year, Francis told those gathered, "Let no one say, 'This you cannot say'." Since then, liberals have tested the boundaries of their new freedom, with one Belgian bishop going as far as calling for the Catholic Church to formally recognise same-sex couples.
Conservatives counter that in the climate of rising liberal thought, they have been thrust unfairly into a position in which defending the real teachings of the church makes you look like an enemy of the Pope.