I like the cut of Professor Reynold's jib:
"Before the declaration, the standard political theory went
something like this: God anointed a king, who is the locus of
sovereignty on earth. Though the king is supposed to rule decently, it
is the duty of everyone else to submit to the king, who is answerable
only to God. The king might grant you rights, but if he did so that was
an act of generosity on his part, not an entitlement on yours."
"Divine-right
political theory was understandably popular with kings and their
supporters and hangers-on, and a form of it survives in assorted
variations today. But the declaration takes a different approach. It
says that rights come from God, not from the king, and that they are
"unalienable" — that is, incapable of being sold ("alienated")
surrendered, or given away."
"What's more, rather than rights coming from the government,
government exists to protect rights."
"Government, in the declaration's
explanation, exists to protect rights, and rather than subjects enjoying
rights with the consent of the government, the government itself rules
only by the consent of the governed. And when the government fails to
live up to its duties, and the people no longer consent to it, it
becomes illegitimate and subject to replacement by something the people
like better."