And I would like to offer this point of view:
I think it was definitely binding. It was binding to the people who signed it and the people who supported it. They committed themselves to it and didn't waver. To them, it was a conviction they felt deep down inside of themselves and was important enough to die for. Paraphrasing Benjamin Franklin, these men had to hang together, or they would surely hang separately.
This summary details what happened to those great men:
"Lives, fortunes, honor...
"Of those 56 who signed the Declaration of Independence, nine died of wounds or hardships during the war. Five were captured and imprisoned, in each case with brutal treatment. Several lost wives, sons or entire families. One lost his 13 children. Two wives were brutally treated. All were at one time or another the victims of manhunts and driven from their homes. Twelve signers had their homes completely burned. Seventeen lost everything they owned. Yet not one defected or went back on his pledged word. Their honor, and the nation they sacrificed so much to create, is still intact.
"And, finally, there is the New Jersey signer, Abraham Clark. He gave two sons to the officer corps in the Revolutionary Army. They were captured and sent to the infamous British prison hulk afloat in New York harbor known as the hell ship "Jersey," where 11,000 American captives were to die. The younger Clarks were treated with a special brutality because of their father. One was put in solitary and given no food. With the end almost in sight, with the war almost won, no one could have blamed Abraham Clark for acceding to the British request when they offered him his sons' lives if he would recant and come out for the King and parliament. The utter despair in this man's heart, the anguish in his very soul, must reach out to each one of us down through 200 years with his answer: "No."
"The 56 signers of the Declaration of Independence proved by their every deed that they made no idle boast when they composed the most magnificent curtain line in history. "And for the support of this Declaration with a firm reliance on the protection of divine providence, we mutually pledge to each other our lives, our fortunes and our sacred honor."
How can you get more binding than that? Death isn't reversible.