If voting had to be unanimous, that would explain why Georgia and South Carolina’s objections carried the day. Jefferson doesn’t tell us what the delegates from the other Southern states thought. I believe it was suggested here that Rhode Island may also have objected, and possibly Connecticut did too. In any case, the necessity of holding the country together (before it had even become a country) meant that one can’t draw conclusions about what the majority of delegates thought about slavery or the slave trade. That it wasn’t considered the moment for such a manifesto didn’t mean that delegates didn’t have serious moral qualms about slavery.
Subsequent debate about the Declaration involved who the document applied to. The original focus of discontent in the colonies had been on what the colonists saw as the King’s violation of their rights as freeborn Englishment. They had the example of England’s previous revolutions as an example. That the Founders invoked a general principle meant that the principle could be applied to and invoked in other cases. Maybe they had to turn to natural law principles in order to justify independence, but that doesn’t matter. They had opened the door to different interpretations of what “men” or “a people” were. They had also opened the door to the idea that revolution and violent wars of independence would always be justified, though I don’t believe that they intended that.
One might look elsewhere in their writings to determine this, but the fact remains they deliberately chose not to make the Declaration about slavery, or to even mention it beyond the reference to "he has incited domestic insurrections among us".
My point remains. Abraham Lincoln making the Declaration about slavery is dishonest. It is deliberately misleading. The declaration was about the very thing he was actively opposing, which was independence for states which wanted it.
They had opened the door to different interpretations of what “men” or “a people” were.
I have long said that Jefferson's inclusions of those words in the Declaration did more to advance abolition of slavery than any other single act by any other person in history.
He created the framework for questioning the idea as acceptable. Everything else descended from that.
They had also opened the door to the idea that revolution and violent wars of independence would always be justified, though I don’t believe that they intended that.
They did not argue for violent war. They argued for a principle that people had a right to be independent and to self government.
Presumably they believed any government founded on such an idea would respect that same principle when others sought to invoke it.
To think otherwise would by hypocrisy.