The Constitution and its amendments are drafted in highly general terms. Edmund Randolph, who wrote the first draft, explained that he had to write it this way so that it would be able to adapt to changing times and circumstances. As to whether we ought to interpret the U.S. Constitution narrowly or broadly; there was no consensus even among the Founding Fathers. It was a topic of hot debate in their time, even among those who together drafted the document, even as they were drafting it. Because of that, there is no definite or final precedent to which either liberals or conservatives can refer to justify their views of the document; the tension which exists between the two ideologies (or something like it) today went into the making of the U.S. Constitution. Because of that fact, the perspective -- "living Constitution" or "strict constitutionalism" -- which prevails at any given point in time will be the one which is most . . . I'll say 'practical'. The perspective which is most practical prevails. But that might be too generous. It might be better to say the perspective which is most powerful prevails.
That things are not explicitly mentioned does not ultimately matter -- or, at least, it does not "have to" matter, depending on which style of interpretation is winning the American political game at the time; airlines are not explicitly mentioned, but they get grouped under a bunch of constitutional clauses anyway. The same thing can occur with health service. I already offered one possible constitutional rationale for how the health insurance program might be legitimized. But I assure you, it will, barring some unlikely upset from the U.S. Supreme Court down the road, be legitimized.
