The Acton Institute asked me for an essay for their publication Religion and Liberty a few months back. Here is an excerpt from the piece I gave them:
As the standard bearer for American conservatism for two decades, Ronald Reagan effortlessly embodied fusionism by uniting Mont Pelerin style libertarians, populist Christians, Burkean conservatives, and national security voters into a devastatingly successful electoral bloc. Today, it is nearly impossible to imagine a candidate winning both New York and Texas, but Reagan and that group of fellow travelers did.
In the meantime, the coalition has begun to show strain as the forces pushing outward exceed those holding it together. The Soviet Union, once so great a threat that Whittaker Chambers felt certain he was switching to the losing side when he began to inform on fellow Communist agents working within the United States, evaporated in what seemed like a period of days in the early 1990s. Suddenly, the ultimate threat of despotic big government eased and companions in arms had the occasion to re-assess their relationship. The review of competing priorities has left former friends moving apart. Perhaps nowhere is the tension greater and more consequential than between the socially conservative elements of the group and devotees of libertarianism.
The two groups have little natural tendency to trust each other when not confronted by a common enemy as in the case of the Cold War. Libertarians simply want to minimize the role of government as much as possible. For them, questions of maintaining strong traditional family units and preserving sexual and/or bioethical mores fall into an unessential realm as far as government is concerned. The government, echoing the thought of John Locke, should primarily occupy itself with providing for physical safety of the person while allowing for the maximum freedom possible for pursuit of self-interest.
Social conservatives similarly view the government as having a primary mission of providing safety, but they also look to the law as a source of moral authority. Man-made law, for them, should seek to be in accord to some degree with divine and natural law. Rifts open wide when social conservatives pursue a public policy agenda designed to prevent divorce, encourage marriage over cohabitation, prevent new understandings of marriage from emerging (e.g. gay marriage or polygamous marriage), prevent avant garde developments in biological experimentation, and a variety of other issues outside (from the libertarian perspective) the true mandate of government that cannot seek to define the good, the right, and the beautiful for a community of individuals. To the degree social conservatives seek to achieve some kind of collective excellence along the lines suggested by Aristotle and Thomas Aquinas, libertarians see a mirror image of the threat posed by big-government leftists.