The model of unchanging Catholicism in response to the Reformation, the Enlightenment and the French Revolution assumed that the church would not change, should not change, could not change. Suddenly the laity and lower clergy experienced changes in liturgy, in Scripture interpretation, in theories of religious liberty, in attitudes toward other Christians and Jews, in trust of the modern world. The structures -- patterns of behavior and supporting motivations -- that had supported the church for several centuries collapsed.
Say what you will about Greeley, at least he is an honest liberal.
Greeley is a sort of SSPX liberal. He hates the papacy and the Church but for his own eccentric reasons. Same behavior/different excuses.