The reaction to Humanae Vitae was a pivotal moment in life of the Church, particularly in the United States. The following footnote from a recent book entitled The Signs of the Times illuminates the behavior of many clergy in the years since the release of the encyclical:

Patrick Cardinal O’Boyle, archbishop of Washington, DC, from 1947-73… was at the center of the dissent aroused by Paul VI’s encyclical Humanae Vitae. Catholic University of America is in Washington, and several theology professors there — namely Fathers Charles Curran, Robert Hunt, and Daniel McGuire — issued a statement, signed by more than 80 other American theologians (which number eventually grew to over 600) who dissented from Humanae Vitae. Cardinal O’Boyle disciplined the clerics. The dissenters then appealed to the Vatican for redress, and the Vatican later sided with them against the Cardinal. Thus was born Cafeteria Catholicism. George Weigel has called the Vatican’s inaction ‘The Truce of 1968,’ which he said ‘taught theologians, priests and other Church professionals that dissent from authoritative teaching was, essentially, cost-free. The Truce of 1968 taught bishops inclined to defend authoritative Catholic teaching vigorously that they should think twice about doing so, if controversy were likely to follow; Rome, fearing schism, was nervous about public action against dissent. The result was that ‘a generation of Catholic bishops came to think of themselves less as authoritative teachers than as moderators of an ongoing dialogue whose primary responsibility was to keep everyone in the conversation and in play.’ And Catholic lay people learned that ‘virtually everything in the Church was questionable: doctrine, morals, the priesthood, the episcopate, the lot.’

from a footnote to an essay entitled “Corinth: The Secular City”