The Preamble is the document's statement of purpose. Saying it is not part of the supreme law is like saying that a foundation is not part of a building.
I didn’t say the Preamble is meaningless. It is very meaningful. That doesn’t make it LAW.
There isn’t a syllable in the Preamble that MANDATES anything. It is a statement about WHO is creating the Constitution, and for what overall purposes.
It is not LAW. It can be neither obeyed nor disobeyed. It commands nothing and forbids nothing.
No one can be coerced to DO ANYTHING or NOT DO ANYTHING on the basis of the Preamble.
It is not LAW. The rest of the Constitution is law. But the Preamble is NOT LAW.