Just to clarify for ML and other non-U.S. FoLCs, the Declaration of Independence does not serve the same function as the Constitution. The Constitution is the foundational document for the U.S. government and is therefore the place where the functions, duties, and limits of the government are laid out. That would be the place to address something like universal health care. It has a process for ongoing 'rivisions.' They're called ammendments. Once an ammendment is ratified, it becomes part of the Constitution and has the same authority as the original parts. The first ten ammendments are the most famous--they're called the Bill of Rights and were a package deal without which some states would not ratify the original Constitution. But there have been others added over time. The most recent is the 26th, ratified in 1971, which lowered the voting age from 21 to 18 years. This was a response to the military draft during the Viet Nam War, the theory being that if you're old enough to fight in a war, you're old enough to vote for or against the guys who sent you. The Contstitution is the final authority for all U.S. laws and courts.
The Declaration of Independence, on the other hand, is mainly a list of grievances against King George III and the British parliament. It was primarily a public relations tool intended to explain the reasons for the American separation from Britain and to elicit sympathy and support from other European nations. (We couldn't have won the war without the help of the French.) It is historically conditioned and, although the preamble is often used for rhetorical purposes, it has no legal authority. There is no reason to 'revise' it because now that we have our independence it's moot. It's done its job.
Here's a link to the text if you'd like to read it for yourself:
Declaration of Independence text BTW, many Americans don't realize this distinction either, so the L&C writers are in good company.
