For something more substantive about the Declaration, you could look to my argument that The Pursuit of Happiness [i]s an Anti-Conservative Principle. This is of piece with my regular posts about the shortcomings of libertarianism as a world-and-life view. (Which can be distinguished--although not entirely separated--from libertarianism as a political philosophy.)
But all of this is preliminary to the following comments about Ruben Alvarado's pre-Independence Day 2015 blast, The State of (Dis-) Union. Alvarado argues that recognition of a Constitutional right to same-sex "marriage" is as American as apple pie because,
The root of the problem is the natural rights paradigm [which characterized the Declaration] that has been put at the heart of Western legal and political institutions since the 17th century, and which from the start was made the cornerstone of the American republic. Simply put, the document signed 239 years ago tomorrow ratified the state of affairs that would eventually produce same-sex marriage.How could it be that Jefferson and others put in motion an understanding of humanity's ends (life, liberty, and pursuit of happiness) such that same-sex "marriage" is its historical (and, indeed, logical) conclusion?
What is this mechanism? The mechanism of subjective right: the individual will, shaping and determining its environment according to its wishes, for its ends, to which it is entitled. This becomes the ultimate source of law. The proper relationship of law and rights, expressed in the doctrine of objective over subjective right, so laboriously elaborated in the centuries of Christian Roman jurisprudence, was reversed in the 17th century; and that inversion, made popular by the appeal to a common humanity so as to supersede religious conflict, gave birth to the jurisprudence which in straight-line trajectory has brought us to the point we are at today, and is poised to take us far beyond.If I can be permitted to restate Alvarado's argument it is that natural rights abstracted from natural law are at the root of our current Constitutional contradiction. Free floating "rights talk," untethered from moorings in the nature of human beings is not, according to Alvarado, something as recent as Jefferson or even John Locke. Indeed, it goes back much further in the Western tradition to Hugo Grotius and includes one of my favs, Samuel Pufendorf. Liberalism, even as classically understood, falls under Alvarado's ban. (For some props about Alvarado's other works go here and here. He's regularly quite right.)
Two comments about natural rights thinking. First, there's much to be said for Alvarado's concern about the notion of rights in the abstract. Nonetheless, drawing from Nicholas Wolterstorff's excellent book "Justice: Rights and Wrongs," I've poked around the foundation of rights here, here, and here and ultimately agree with Wolterstorff that there is a legitimate place for "rights talk." Even without buying into the all the quiddities of the Western tradition of natural rights, there is a foundation for rights in humanity's creation in the image of God. Alvarado may well agree that rights exist but I'm not as confident that he would agree they have warrant except insofar as they arise in the full-blown context of that tradition. Yet even without a proper metaphysical and anthropological foundation, rights exist.
Second, I'm a bit more partial to the liberal tradition than Alvarado (although I'm less Whiggish than John Witte). You can read my article, Looking for Bedrock: Accounting for Human Rights in Classical Liberalism, Modern Secularism, and the Christian Tradition (download here) to find out why. For a shorter version, check the post by Peter Escalante here with which I am in substantial agreement.
In short, classical liberalism through the end of the 18th century had more in common with the pre-modern political theology of Christendom than it did with the revolutionary and secularizing "progressive" trends that gained traction over the course of the 19th century. Liberalism may have contained within it certain seeds of its own destruction but the flowering of those seeds owes as much to historical contingencies as it does to the liberal tradition as such.