The DoI is not a contract between the government and the people as the Constitution is, it’s just a set of principles. It doesn’t make them any less sacred in terms of what the Founders believed or what Lincoln believed and like the Constitution we are more or less dedicated to living by them, although the Constitution actually backs up the DoI with the force of law. That’s the difference.
exactly — I don’t for an instant question the enormous and fundamental importance of the Declaration of Independence, and I think it was a tremendous thing for Lincoln to create this evolving sense of nationhood from 1776 to 1863, but the legal and “constitutional” fact is that there was no USA before 1788-89.... one can point to fundamental ideas extending back even well before the Declaration, in terms of certain aspects of the colonies.... but how can one say there was a “constitution” in existence before or during the Articles of Confederation?