The United States Constitution is the set of rules that animated the United States. It caused it to come into being. It's The Law.
The document serves two functions: It details a set of rules by which government officers are to act. And its simple wording and structure serve as a guide to the common man. It's like a Field Guide to North American Birds. It describes to the common man the nature of the species in question. It communicates to him the behavior of that lawful government. If what is, is not what is described then the common man may righteously ignore it; obviously something has gone awry.
If it doesn't have a posterior white patch and a half-moon white stripe by the eyes, then it's not a Blue Winged Teal.
Got it?