The coming (current) clash between post-modern, superficially liberal, secular states and the great religious tides crashing against them cannot possibly be resolved by liberal or conservative principles. The usual give and take of politics is insufficient to meet the zealous, unevolved religions demanding their place in the Western sun.
Or, as Churchill said, "A fanatic is one who cannot change his mind and will not change the subject."
The current state of Western politics is founded on Universal Commercialism. Liberals and Conservatives wage war to determine where the individual will fit within the fabric of the larger culture. Neither owns a monopoly on righteousness, or practically recognizes righteousness, at all. Neither liberalism nor conservatism is actually about spiritual or religious righteousness.
Liberal principles (always) promote the rights/privileges of the individual over the larger group. Hence, the convoluted linguistic gymnastics necessary to accommodate various hygienic practices as "rights of privacy."
Conservative principles (always) promote the rights/privileges of the individual apart from the larger group. Hence, the jarring sight of five term Congressmen meeting with Tea Party groups to establish themselves as "Outside Politicians."
Please note: the underlying principles of both political schools remove the individual from the greater group. Christianity, as a revealed and evolved religion, is set on principles that deeply respect the rights of the single person (individual salvation) set in the midst of the greater group (the assembling of ourselves together). The unevolved (unadapted ancient faith systems based on nihilism or race hatred) religion cannot (will not, and force of will is destiny in this regard) accept the citizen (or, finally, the culture) apart from its own practices. Torah Law and Sharia Law and Hindu ethics must have exclusivity quite because they are unevolved and, so, like their political cousins (liberalism and conservatism) have no place for the individual within the larger group, outside their religious community.
That is, for the unevolved (see definition above) membership in the religious community is the only significant category of membership. Dogma, doctrine and discipline of one's own religious nature matter; nothing else. When religious community membership confronts the larger culture with mutual claims of exclusive significance the results have names like Wounded Knee, Cawnpore, the West Bank or Kurdistan.
The result is either violence of the culture against religion or religion against the culture. Vitriolic demonstrations at the graves of fallen American soldiers because they defend a nation known to harbor homosexuals is not much less rational than the isolated murders of abortion doctors by other single issue doctrinaires. Each, remember, removes the individual from common life within the larger group.
These are small matters (except to the persons intimately offended). The larger clash between massive immigrating populations insistent on their practices in the midst of the larger culture is potentially more serious. Superficial liberalism, with its insistence that all religions the same does not actually respect religion of any kind, for it means that one religion is about as worthless as any other. This will not do with the zealous practitioners of the unevolved religions. Superficial conservatism would defend religion from its own evolution with the attendant concerns mentioned previously.
No, only Christianity will do. Secularism will not suffice. When man loses sight of the spiritual reality of God, man also loses his moral restraints, as the Wisdom writer tells us in Proverbs 29:18. People do whatever they wish when they do not believe there is a personal God who wants something better of them.
Evolved Christianity, with its understanding of universal sinfulness and hope of universal salvation, can give respect to its own various branches, even the wild branches, as it has demonstrated. Neither liberal nor conservative post-modernism has demonstrated such an art. Ergo, Christian principles and practices cannot be excluded from American culture (except to the peril of this culture), lest the culture itself lose its potential buffer between the zealous religions arising in the East and Mid-East and the secular, post-modern culture that liberty, fraternity and equality have mid-wifed in the last two centuries. France, Germany now (2010) experience the trauma of a secular social order aggrieved by an unevolved religion with no religious underpinnings of their own as a larger culture. The result will be violence of one side against the other or of surrender of one side to the other.
Opinions expressed here are mine alone.