A couple points to start this off.
The liberal element in the Church, progressivists, the Fishwrap and Bitter Pill types, want the Catholic Church to become, at the least bad end of the scale, like the Church of England or otherwise something more congregationalist. They want less clear or no hierarchy (unless they are in charge) and less systematic doctrine. They want less transcendence and more immanence. They want a church that goes along to get along.
Another point to consider is that catholics such as Rep. Nancy Pelosi, VP Biden, Sec. Kathleen Sebelius, etc. pro-abortion quislings, would be content with an American Patriotic Catholic Association, a state-controlled church which could be used, when convenient, to promote their political and social engineering agenda.
The Church of England, which in my opinion should immediately issue their document Romanum coetibus, is demonstrating why all of the aforementioned is a bad idea. You see, the Church of England, as the established church, the church of the state, under the Crown, must by its very nature go with, and not against, secular trends. It may be slow in moving, but it is inevitable that it will to in the direction of popular trends and mores.
At the the site of the UK’s best Catholic weekly, The Catholic Herald, there is an article by William Oddie about the debate in the Church of England about women bishops. Take your time to read the whole thing. It is worthwhile and informative.
What I found so interesting was the fact that, in this debate about women bishops, some Members of Parliament are getting involved. They are not involved on theological grounds, but on state/secular/legal grounds.
Oddie writes (my emphases):
The Church of England is established by law under the crown; it is the state Church, so we too have a stake in it. Ultimately its affairs are regulated by Parliament: when, that is to say, the Synod has legislated to establish a female episcopate, its legislation must be taken across the road and translated into English secular law by both the House of Commons and the House of Lords. Then the Queen must give her assent. All this would normally be a formality: whatever the Synod wants Parliament usually lets it have. It has been little noticed, however, that this time, members of the 30-strong parliamentary committee of MPs and peers known as the “ecclesiastical committee”, which would have to agree that the Synodical legislation is “expedient” before it proceeds on its weary way, are saying firmly that any “special arrangements” for dissident parishes would not be accepted by them. [Get that? Oddie here is referring to the possibility that, in the event of women bishops, there might be "flying bishops" (love that image) who would be 2nd-class bishops.]
This is, of course, for entirely secular reasons, as members of the ecclesiastical committee are making clear: the Synod’s legislation will have to conform with the Human Rights Act. That means that the “special arrangements” the House of Bishops want incorporated into the new law will not get past Parliament. “This is now the second time the bishops have tried to water down the proposals,” says Ben Bradshaw MP, a member of the parliamentary committee. “These would, in the eyes of many Anglicans, create a two-tier bishopric and a lesser status for women… I have spoken to some of my colleagues on the ecclesiastical committee and they share my concerns about the amendments.”
Simon Hughes MP, another member of the committee, says that its members have a “duty” to ensure the proposals do not conflict with equality law. “The ecclesiastical committee obviously does not set out to impose its will on [the Church], [Is that so?] however we have a duty to make sure that anything that comes before us does not break any of the principles of the law of the land,” he said.
Thus, you see what happens where there is too much Church/State entanglement.