Now that citizenship has become an alien concept to most Americans, the distinction between citizen and non-citizen is being obliterated. Decades ago. Justice Thurgood Marshall was already making the case that aliens, even illegal aliens, should—or, rather, did—enjoy virtually the same rights as citizens, and recently we have heard the claim (from “conservatives”) that the last distinction enjoyed by native-born American citizens—namely, the capacity to be elected president—should be abandoned.

The word “citizen” is derived ultimately from Latin civis, which signified a member of the Roman commonwealth. Like the Greek polites, civis designated two qualities: someone who dwelled in an organized commonwealth like Athens and who enjoyed all the privileges of the commonwealth. Citizens served in the army and on juries; they were exempt from the kinds of taxes that are levied on subject states; they were eligible to hold public office and to vote. In England, “citizen” has been used in both senses.

England was a monarchy in which the key political concept was not citizenship but subjection to the crown. Because the barons who held estates on both sides of the Channel often displayed doubtful loyalty to the crown, Norman England developed the concept of ius soli: You were an English subject if you were born on English soil. Ius soli citizenship made sense in the context of an island state and an Anglo-Norman aristocracy of divided loyalty; in America, it has made nothing but mischief, since an illegal-alien woman may unilaterally impose her child on the American commonwealth, so long as the child is born in the United States. We would have been better off had we adopted the more common notion of ius sanguinis, by which only the children of citizens (wherever they happen to be born) are citizens.

All of that is moot now, of course. Like the Roman emperors who gradually extended citizenship to virtually every free person within imperial territory, the American government has so liberally minted citizens out of aliens that the very concept of citizenship has become foreign (pun intended). Citizens are a dangerous bunch. As William Jennings Bryan put it, “The humblest citizen in all the land, when clad in the armor of a righteous cause, is stronger than all the hosts of error.” Not anymore. We have been transformed into domesticated subjects rather than sturdy citizens, and our primary relationship to the state is based on obedience, not on the exercise of civil privileges. It was all in a good cause, of course. “Before man made us citizens,” canted James Russell Lowell of fugitive slaves, “Nature made us men.” And so all of us—native citizens, naturalized citizens, green-card aliens, “undocumented workers”—have been made in the image of nature, as free as rabbits and rocks.