The Declaration of independence - our founding document - is very clear on citizen's rights.

[elehhhhna]

We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. — That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, — 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.

[gratuitous]

1. Unfortunately, the Declaration carries no legal weight

However, the preamble to the Constitution clearly states that one of the purposes of the federal government it describes and establishes is to provide for the general welfare of the citizens, which would include making sure they're fed, housed, clothed, and healthy.

[Orsino]

2. It's just not clear on who gets to be a citizen and have rights.

Some restrictions apply.

[Voltaire2]

3. It provides an ethical framework not a legal one.

Plus of course it is also a document that describes the rights of white men. Women and non Europeans are not part of the equation. Jefferson removed the one reference to slavery from the final document and more than 40 of the signing white men were slave owners.