Nobody actualy agrees with the Declaration of Independence anymore
Well, that's putting it a bit strongly, but saying "<20% of the American population agrees with the Declaration of Independence" doesn't have quite the same punch to it.
Every July 4th, people intellectually genuflect in the direction of our founding documents, but nobody actually thinks about the meaning of these words:
That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness.These words mean that, in principle, secession from a political state is both possible, and sometimes necessary. But mainstream opinion has it that secession from the USA is both unthinkable and immoral - tainted by association with the Confederacy's battle to preserve slavery. But if you take these words seriously, the Declaration of Independence implies that it should be possible for states to secede peacefully if the people no longer believe that the federal government is securing their "unalienable rights".
Some food for thought on your independence day.