In recent decades, West observes, this idea of the political thought of the founding as mixture of different and sometimes conflicting intellectual traditions has become the predominant scholarly consensus, which Zuckert shares with scholars like William Galston, Thomas Pangle, and Paul Rahe. But West complains that this makes the founders appear to be confused or incoherent in their thinking. Against this, he proposes to explain the natural rights theory of the founders as a theoretically coherent understanding of politics without any tension or contradictions.
Nonetheless, a careful reading and comparison of West's and Zuckert's books will show, I think, that West's explicit rejection of Zuckert's "amalgam thesis" is contradicted by West's implicit acceptance of Zuckert's argument. Although this might seem to be a trivial scholarly quibble, it points to some of the fundamental questions about the American political regime and about the theory of natural rights as applied to that regime.
". . . what made America was the way these four elements--Old Whig constitutionalism, political religion, republicanism, and the natural rights philosophy--come together. The amalgamation that occurred in America was unique in the world, and led America to a unique path of political development and to a particularly tense existence as these four different and, in some dimensions, incompatible elements fell in and out of harmony with each other. In that amalgam, however, the four elements did not all enjoy an equal status; the natural rights philosophy remains America's deepest and so far most abiding commitment, and the others could enter the amalgam only so far as they were compatible, or could be made so, with natural rights. The truly remarkable thing is the demonstrated capacity of the natural rights philosophy to assimilate the other three and hold them all together in a coherent if not always easily subsisting whole" (Zuckert 1996, 95).West quotes some of this language--"tense existence . . . incompatible elements"--as suggesting that the political thought of the founders was an incoherent mixture of contradictory elements; and against that idea, West claims that he can show that the natural rights philosophy of the founders was fully coherent and free from any tense contradictions (West 2017, 46).
But notice that Zuckert sees this American amalgam of different elements as rendered coherent by the preeminence of natural rights as the ruling element, so that the other elements can enter the amalgam only in so far as they can be made compatible with natural rights. Thus, Zuckert can describe this as "an amalgamation in which the natural rights commitment has remained senior partner but has brought into its political orbit English Whig historical commitments, Protestant political theology, and premodern political republicanism" (240-41).
West seems to agree with this, because he says that the success of the American Revolution required a combination of natural rights thinking with the "distinctive ethnic character, religion, and legal heritage" of America, and to that extent, he concedes, "the amalgam thesis is correct: natural rights are not enough." But just as Zuckert speaks of natural rights as the "senior partner" in the amalgam, West speaks of natural rights as taking the "leading role" (West 2017, 52).
So here West and Zuckert agree on the amalgam thesis: that the political thought of the founding was a mixture of historical, religious, and political traditions, but that the natural rights philosophy was the preeminent element in that mixture, so that all the other elements had to be somehow assimilated into that natural rights thinking.
West also recognizes, at least implicitly, some of the same "tension" that Zuckert sees between natural rights thinking and some of the other elements of the American amalgam. For example, Zuckert shows how the Lockeanization of New England Puritan thought required the rejection of the Puritan theocracy that prevailed in the colonial period. Similarly, West shows how the theory of natural rights required moving away from the governmental enforcement of Mosaic theocracy towards a separation of church and state, so that "government is no longer in the business of defining the one true religion," and "individuals are free to live their lives independently of religious faith" (407). The tension between Protestant Christian theocracy and Lockean religious toleration was softened if not overcome by deciding that Roger Williams was right that Protestant Christianity required a "wall of separation" between "spiritual things" and "civil things."
West, Thomas G. 2017. The Political Theory of the American Founding: Natural Rights, Public Policy, and the Moral Conditions of Freedom. Cambridge: Cambridge University Press.
Zuckert, Michael. 1996. The Natural Rights Republic: Studies in the Foundation of the American Political Tradition. Notre Dame, IN: University of Notre Dame Press.