"Why would we want it "back"?"
Well, considering how that 'Goddamn Piece of Paper' is the only thing ensuring your pwecious 2nd Amendment & religion's right to exist, you tell me.
That scene in "World War Z", in which the actual US Constitution was saved from the oncoming Zombie Apocalypse: such is it's importance, that scene alone speaks volumes of how such would be needed as the basis of rebuilding a civilised nation.
Even Stevie Wonder could see the metaphor that scene represents. If only you & all your ilk could too.