So I take it you believe the Constitution should be rewritten. Sigh. No wonder I don't understand people who don't like Miers.
Every decision that is made rewrites the Constitution to some extent because it is dealing with a question the framers did not anticipate.
The constitution was never meant to be the final word. It is a set of basic principles that provide the foundation of American law. Just as church tradition/Talmudic interpretation expands upon scripture, so legal precedent expands upon the constitution in response to changing situations.
No, the Supreme Court decides cases where the Constitution has not been applied before and where the outcome is not clear. That is how they get to the SC (9th circuit foibles aside). It is sort of like applying the theory of turbulent aerodynamics to a fighter aircraft that is to operate at a higher AOA than anything before. The basic principles might be very clear (or not, in this case), but the application and outcome require a lot of hard work, argument, testing, etc.