You've got to think of the Constitution as more of a framework than an enormous set of "cans" and "cannots." When it was ratified it distributed power between different instruments of government (separation of powers), created a government whose power was checked by other parts of government, and much more. It did not, however, really address personal rights and freedoms. Remember: the Bill of Rights lists the the freedoms enjoyed by all Americans, and it was added after the Constitution was ratified.
