The short answer: the number of times the Supreme Court has ruled on a constitutional question. Every time the Supreme Court grants certiorari, allows a case to move ‘upwards’ from state and Federal courts to its chambers, and then proceeds to rule–keeping in mind the supposedly relevant precedents, and on the basis of a coherent theory of the interpretation of legal texts–it offers us an amended constitution. Every act of interpretation–sometimes plain literalist, sometimes originalist, sometimes purposive–adds meaning and texture to the text of the articles of the Constitution. Thus the content of the Fourth Amendment is not to be found in the Constitution; it is to be found in the cumulative history of all Supreme Court rulings on cases that have rested on contested interpretations of the Amendment. What does ‘unreasonable’ mean? What does ‘search’ mean? What does ‘seizure’ mean? What does ‘persons’ mean? What does ‘effects’ mean? What does ‘probable cause’ mean? To decipher this meaning, scattered over thousands and thousands of pages of Supreme Court rulings is an almost insuperable and intractable task; it is much easier, therefore, to fall back on the simplest formulation of all: ‘The Fourth Amendment says that…’. But the filling out of that particular that-clause will call for the expenditure of considerable ink, and in the end, it will appear that the protections of the Fourth Amendment are considerably more ambiguous–in several dimensions–than previously imagined, by both its detractors and proponents alike.
These considerations show that talk of ‘constitutional protections’ must always proceed hand in hand with talk of constitutional interpretation, with the history of actual supreme court rulings on the constitutional question under discussion. Such inclusion is especially necessary when giving someone legal advice; as Justice Holmes sagely pointed out many years ago, the law is what the judges say it is: “The prophecies of what the courts will do in fact, and nothing more pretentious.”
Our nation is entering a period of great legal uncertainty; there is much talk of taking cover under constitutional protections, of seeking refuge from an authoritarian government under the covering canopy of the Bill of Rights. But the text of the Bill of Rights is not sufficient to provide such protection; the Supreme Court rulings on Bill of Rights cases are far more germane. To look only to the Constitution is dangerously complacent; talk of legal rights without actual legal protections is hollow.
Many a patriot is disappointed and disillusioned to find out that in point of fact the Fourth Amendment is almost hollow in content; its protections systematically eviscerated over the years by repeated weakenings through selective, ideological, and politically motivated interpretation. Mass surveillance; warrantless searches; stop and frisk; the list goes on. Where is the Fourth Amendment?, the patriot asks. The answer is: not in a small booklet, but in that section of the law school’s library that deals with constitutional law.
Constitutional conventions, two-thirds majorities, ratifications by state legislatures–such is the machinery of the constitutional amendment by legislative fiat. Such convolutions are kludgy compared to the awesomely efficient method of Supreme Court rulings; there, in the foundry of the Supreme Court’s chambers, new meanings are forged every year, every Supreme Court season.