I was not trying to disparage you or your argument nor was I calling YOU a Straussian, but your position that the Declaration of Independence somehow is a “founding” document is a Straussian position.
The Declaration is not a “public description of what we considered good government in 1776.” It was a “defounding” document if nothing else. Certainly, it was an expression of the American mind as Jefferson said, but the only portion of the document that could be taken as a reference to government is the last paragraph where Jefferson announces that there are 13 Free and Independent States similar to the State of Great Britain. The second paragraph were historians and Americans in general focus so much time and energy was a justification for why Americans believed they had a right to secede from the Empire, i.e. longstanding abuse of English liberties.
That is where I think your entire premise is wrong. The Declaration was never intended to be a “vision” for American government. The vision for American government could be found in British and ancient antecedents. As John Dickinson said, “Experience must be our only guide.”
The Constitution failed to achieve what proponents said it would, namely a federal republic of delegated powers, because the States ultimately did not have the codified legal authority to check federal usurpations of power. They thought the language of the 10th Amendment would be enough. They were wrong.