Some final thoughts here.  Not sure this is all going anywhere really, but I wrote this up, so here it is.

An advantage enjoyed by Murray in his attempt to enshrine natural law theory as America’s ‘public philosophy’ comes by way of his insistence on rooting it in the historical development of American liberalism rather than in a proper philosophical theory.  While NLT has been developed as a philosophical theory in great detail, and is defended as such by Murray, ultimately the ‘Murray Project’, as some have come to call it, depends more on its making sense of America’s history, its founding documents and ideals in particular.  Murray and his followers would make NLT public by leveraging the highly familiar language of the Declaration of Independence and giving it a natural law reading.

By these measures Rawlsian liberals face some difficulties.  Political liberalism can make sense of some perennial American political challenges, church-state relations being foremost among them.  But it cannot be argued that it captures much of the American liberal tradition’s self understanding.  Although it allows us to construct powerful models of the liberal state, it’s less able to capture the philosophical commitments that historically made sense of things like rights, freedom, and equality.  Consequently It is even more plain that political liberalism cannot be plausibly read into the founding documents.  Lastly, and for these reasons, it is difficult too to see how political liberalism can be packaged in a way that renders it vivid to audiences unlikely to work through the philosophy.

That said, I think it is fair to say that Murray’s NLT has some strategic problems of its own, some of which I gestured towards earlier.  I’d concede that Murray’s history of American liberalism has something to be said for it, and that the founding fathers at least often sound like Natural Law theorists.  For good or ill, however, NLT remains on the intellectual margins (though less so in recent years), and its language and many of its conclusions sound decidedly odd to modern ears.  That it is so closely tied to a specific religious faith is also a serious obstacle.

Aside from their own weaknesses, these two competing proposals are both bedeviled by the ascendency of a rival would be ‘public philosophy’, namely libertarianism, and in particular, a highly individualistic version that tends towards relativism and emotivist moral thinking.  (I’m following MacIntyre here in using “emotivism” to name a rather simplistic belief that moral judgments are merely expressions of private feelings.)  Its extensive philosophical shortcoming notwithstanding, in some respects it would seem libertarianism is well suited to function as a unifying framework for a pluralistic liberal society by supposing a radical parity between all ideas and beliefs and rooting whatever unity we might preserve in the ideal of tolerance.  If the curious appeal of Ron Paul is any indication, libertarianism also works in the minds of many to make sense of American democratic ideals.  What it probably can’t do–and again this is aside from its philosophical shortcomings, which I think are extensive–is maintain or foster enough of a consensus in underlying values and commitments to ensure political disagreements remain political.