The US Constitution is not just a set of guidelines, it is law. This is not simply a matter of opinion, it's written into the Constitution itself. Article 6, Section 2 of the Constitution states:
"This Constitution, and the Laws of the United States which shall be made in Pursuance thereof; and all Treaties made, or which shall be made, under the Authority of the United States, shall be the supreme Law of the Land;"
It is not simply a set of guidelines for making law. It is law.
Get the best-written book on the US Constitution here. See the original text and compare to the modern English version, with commentary on key sections.