Wow! that is really a lose interpretation. Nothing like reading something into a document that says no such thing. You must be a liberal constitutionalist.
"We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defense, promote the general Welfare, and secure the Blessings of Liberty to ourselves and our Posterity, do ordain and establish this Constitution for the United States of America.""...to ourselves and our Posterity..."
You claim that I am a liberal because I interpret those words in the Preamble to mean to "us and everyone that comes after us."
Let's play a game.
You tell me how "to ourselves and our posterity" means something other than to us and everyone that comes after us, and how that does not indicate perpetuity.
If you have to use more words than I did, you lose.