liberty, or property, without due process of law; nor deny to any person
within its jurisdiction the equal protection of the law.

We have lived so long under the protection of these rules that most of us
have forgotten their importance. They have been unquestioned in America so
long that most of us have forgotten the reasons for them. But if we lose
them we shall learn the reasons by hard experience. And we are in some
danger of losing them, not all at once but gradually, by indifference.

As Professor Sohm says: "The greatest and most far reaching revolutions in
history are not consciously observed at the time of their occurrence."

Every one of these provisions has a history. Every one stops a way
through which the overwhelming power of government has oppressed the
weak individual citizen, and may do so again if the way be opened. Such
provisions as these are not mere commands. They withhold power. The instant
any officer, of whatever kind or grade, transgresses them he ceases to act
as an officer. The power of sovereignty no longer supports him. The majesty
of the law no longer gives him authority. The shield of the law no longer
protects him. He becomes a trespasser, a despoiler, a law breaker, and
all the machinery of the law may be set in motion for his restraint or
punishment. It is true that the people who have made these rules may repeal
them. As restraints upon the people themselves they are but self-denying
ordinances which the people may revoke, but the supreme test of
capacity for popular self-government is the possession of that power of
self-restraint through which a people can subject its own conduct to the
control of declared principles of action.

These rules of constitutional limitation differ from ordinary statutes in
this, that these rules are made impersonally, abstractly, dispassionately,