Hi Gunslingr,
The following are just some highly fallible opinions and observations of mine as to some of the reasons we are seeing the widening worldview rift in American culture.
We often forget that as Western first world nations go, America is the last of the nationalistic, politically conservative, predominantly religious nations. The vast majority of the other first world nations have embraced some form of soft Socialism and abandoned theism for atheistic or agnostic worldviews (materialism, existentialism, nihilism, etc.) We may complain about the liberalism of Canada, but we forget that worldview-wise, they are closest to the USA in their outlook.
Anyway, there is tremendous pressure within this country, especially within our intelligentsia, for us to abandon "outmoded" ideas like nationalism, conservatism and faith and follow the outlook of the rest of the first world nations, and increasing frustration that nationally, we aren't. We are rapidly reaching an ideological impasse which historically has only been resolved by Civil War or Revolution. Increasingly, we can't communicate or peacefully coexist with one another, and the level of hatred and antagonism is beginning to boil over. Our discourse is increasingly simply irrational - for instance Bush getting blamed for Hurricanes, or accused simultaneously of being too stupid to write his name and a sinister mastermind willing to blow up the WTC in pursuit of "Hitler-like" power. Chimp Hitler - the fiendish amoral conspirator genius capable of fooling the majority, who is also a prudish transparently brain-dead idiot. He has ceased to be a human being and has become an icon. He is the incarnation of everything the left hates about the right, the atheist hates about the evangelicals, the socialist hates about the capitalists, the environmentalist hates about the industrialists. This is just raw hatred and frustration, pure and simple.
There is also the huge divide on social issues, those who do not believe in absolutes and insist on positive law rather than any form of natural law have no basis for dialogue with those who do believe in absolutes and God-given laws. Were can you go when we have an argument between those who say "I am all there is, I decide" and those who say "God is there and He is not silent."
It seems to me as I try to recall the first hand material I've read, that the levels of contempt between the opposing ideologies are currently either at or above the those that existed between Torries and Patriots, Abolitionists and Slave Holders. However, we also live in the media-driven/apathy/leisure age which impedes the outbreak of actual violence. It seems as if at present revolt is not being kept in check by our prosperity - keep in mind also that America's two great revolts were primarily ideological and not inspired by economic deprivation - if anything we are kept in check by our vices.