The Declaration has no legal bearing on the interpretation of the Constitution, as it was not “integrated” into the Constitution.
That whenever any form of government becomes destructive to 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.So, when someone is "interpreting" the Constitution to mean that the federal government is constitutionally able to spend trillions of dollars on what a relative small number of politicians decide is for the "public welfare," the Declaration gives the people of the nation the authority to override this "interpretation," even by means of force of arms, if necessary, to restore the federal government to the original founding principles set forth in the Declaration.
The Declaration is the first document in the US Code.
http://uscode.house.gov/download/pls/organiclaws.txt
To deny the Natural Law basis of our founding is to reject the basis of our Constitution. “That to secure these Rights, Governments are instituted among Men,” are not empty words.