Hello my fellow Americans that are reading this post (to my international friends, thank you for visiting on this momentous day for the United States of America). Anyway, some legal scholars will always have differing opinions, but I do side with the group that says the Declaration of Independence is NOT a legal binding document. It is NOT a contract.
Rather than wasting your day off with legal philosophy, just think of the act of the Declaration of Independence as a repudiation of a "contract" that is that the colonies had with the crown of England. However, notice with normal contract law, that a court has the power to enforce or direct damages against the breaching party.
In our country's great struggle for freedom and independence we repudiated our connection to a despotic king's attempt to control our colonies. The way to enforce this "contract" - through force of arms, i.e. the Revolutionary War. However, as a legal document, the Supreme Court, does not find the Declaration of Independence as substantive law.
I think that this legal podcast explains the situation quite well. In short, our Constitution enshrines many of the sentiments of the Declaration of Independence, which is a binding legal document. While, I am sure you probably want to discuss this more given the Supreme Court's rulings from the past week, take a breath and enjoy your day and declare some freedom from the stress of the work week!
Happy 4th of July!