The Declaration's preamble seems a very meager foundation for principles. Here's its take on the foundation for principles:
That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness.These principles seem quite pragmatic. The DoI then goes on to invoke prudence. I doubt we can truthfully claim an American ideology to have been in continuous existence from the time of the War of Independence to the present.
And as you must well know, you actually skipped the beginning of the Declaration. You seem to be trying to avoid something:
When in the Course of human events, it becomes necessary for one people to dissolve the political bands which have connected them with another, and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature's God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation. We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.--That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed....
Considering what these words say upon their face and the documented political ideology which they represent, the aim of conserving, and further winnowing out, applying and building upon the principles of our national inheritance is a strongly ideological pursuit.