Did you misspeak? The Declaration is indeed Fundamental Law.It declares the principles our Us Constitution purports to agree with and uphold. The principles of the Declaration are codified in several of the State Constitutions if not their Enabling Acts which authorize the constitutions.No mere editorial that.
Constitutions codified the principles.
But as far as being “law” the declaration is not and was never meant to be law.
Go into a courtroom and try to use it as a point of law. The judge will give you a harsh lecture. I’ve seen it first hand.
The the judge will assign you competent counsel.