The Constitution that emerged from the Philadelphia convention in 1787 did not seriously address civil liberties. During debates over ratification, the Antifederalists argued that, by failing to provide explicit protections for individual citizens, the new Constitution invited tyranny. Bowing to political pressure, James Madison agreed to introduce a bill of rights during the first Congress. Its provisions limited the capacity of government to impose heavy conformity costs on those whose views differ from the majority.

Though the Bill of Rights provides a clear statement of the “fundamental maxims of free governments,” they were not initially applied to state laws and practices. Indeed, until the late nineteenth century its protections were virtually meaningless, as most disputes involved state governments. The Fourteenth Amendment, which gave the national government the power to protect former slaves, opened the door to the nationalization of civil liberties. It states that all persons enjoy the same civil liberties and rights, and that states cannot deny these without due process of law.

Under the cover of the Fourteenth Amendment, a long series of decisions by the Supreme Court gradually extended the Bill of Rights to state laws and practices. This process of incorporation altered the balance of power between the national and state governments, and expanded the range of protection offered by the Bill of Rights.

While the language in the Bill of Rights is clear and unequivocal, its application is not. For example, what if two or more guaranteed liberties come into conflict? Furthermore, new technologies and modern lifestyles have created novel civil liberties dilemmas.

The exact boundaries of the protections offered by the Bill of Rights are set and reset by a few unelected federal judges guided as much by personal, partisan, and ideological preferences and needs posed at times of war and other crises as by their understanding of the law. The responsiveness of judges to these political and institutional exigencies often keeps the federal courts from deviating too far from public opinion. If history suggests one certainty when it comes to civil liberties policies it is that they will be continuously revisited and frequently revised.