The Legion of Decency -- The Ascent

A question that consumes me: how much influence did Christian values, in either a genuine or secularized form, have over mass media in, say, the period between 1910-1960, and when, why, where and how did they lose it?
One estimable organization that I knew very little about is the Legion of Decency , the Roman Catholic organization that policed Hollywood through its classification system, its ultimate weapon being the "C" rating, C standing for "Condemned".
Like most everyone else brought up in this culture, I grew up sneering at the film industry's voluntary self-policing through the Hays code. It does seem rather harsh in retrospect that until 1961, a female navel had never been seen in a major-studio American picture (the groundbreaker being Christine Kauffman in Town Without Pity.) But the briefest glance at the culture today reveals that something has gone horribly wrong; perhaps we should have a little more respect for the work of those who acted as salt, delaying the putrefaction of the culture by some decades.
I've been reading James M, Skinner's The Cross and the Cinema (London: Praeger, 1993) on the L of D. I never realized how much influence the Legion had on film content. In the early 1930s Catholics began to come to the judgment that Joe Breen's administration of the Production Code was insufficient to protect American morals. Example: in 1934 Cardinal Dougherty of Philadelphia told Catholics to stay away from all theatres in the city entirely "not merely as a counsel but a positive command, binding all in conscience under pain of sin." (35) Box office receipts fell by 40%. Catholics began to think of forming a national policing organization with the full weight of the hierarchy behind it. By adopting a uniform stance across the country, the Church could wield more influence on the studios. Then an organization could go beyond merely classifying and condemning to encouraging studios to make changes to films to avoid full condemnation, thereby achieving actual improvement in the moral quality of films. (In addition, overuse of outright condemnation raised the possibility of Catholics ceasing to follow the Legion's lead, a deadly danger always kept in mind).
The early Legion was not interested in the quality of entertainment, but in morality pure and simple. Seduction and adultery were never be depicted favourably, and ideally not depicted at all. Divorce was never to be depicted as the best solution. The Legion was also on the lookout for more dubious targets such as wise-cracking career girls refusing to display feminine decorum.
I will pass over discussing the Legion's effectiveness by deeming it very effective. When a bishop directed all his parish priests to declare from the pulpit that anyone viewing a film committed a mortal sin, or threatened that any theatre showing a condemned film would be boycotted for one year after its exhibition, results followed.
The question of interest is -- why did the Legion fail in its task so dramatically in the 1960s?? Did Catholics stop following its dictates? Did post-Vatican II liberalism subvert the Church's purpose and will? Did the force of the sexual revolution simply overwhelm the Legion -- it would be hard, after all, to persuade the faithful to avoid 90% of the films Hollywood makes?
As we will see, the Legion was undermined in the 50s by authoritative pronouncements by two very powerful bodies. One, unsurprisingly, was the United States Supreme Court. The other, very surprisingly, was none other than Pope Pius XII.