most liberals have accepted, consent to membership must benmutual, expressed by the existing community as well as bynthe individual. Otherwise, existing members will be coercednand their free choices nullified. But this requirement mightnimply that a society could deny outsiders opportunities fornmembership in ways that are harshly restrictive or discriminatory.nIt might also mean that a society could freely denationalizencitizens against their will, reducing their security andnstatus, perhaps even leaving them stateless. In both these instances,nadherence to consent may well violate liberalism’snother deep commitment to insuring that the basic humannrights of all be secured as fully as possible. As noted above, thentension between government by consent and full protection forninalienable rights, visible in liberal theory almost from its inception,nis dramatically evident if a democratic governmentndenies all obligation to those who are compelled to turn to itnbut who are not admitted to be its citizens.nThe difficulty points in turn to a third, related problem.nThe notion of consent is far from being a self-defining concept.nIt necessarily requires assumptions about several highlyncontroversial questions, such as the scope of free will, the naturenof informed choice, and the availability of alternatives. Bynrelying upon notions such as tacit agreement, it may evennsmuggle in elements of ascription. In the context of consensualncitizenship, moreover, the requirement of mutuality maynseem to render individual consent hollow in practice becausenthose to whom a state refuses consent may have no practicalnoption to go elsewhere. Persons faced with a choice of onlynlimited, exceedingly harsh alternatives may be more aptly describednas compelled than free to choose. More generally, nonclear, unproblematic boundary exists between the realms ofnconsent and coercion.nFourth, there is a problem of unlimited expatriation. Thenconsensual principle in its purest form is literally anarchical,njeopardizing all memberships and allegiances. Although somenliberals insist that rational individuals can recognize the imprudencenof promoting social instability, political societiesnprobably could not survive if their citizens felt free to renouncentheir memberships unilaterally whenever it seemed convenientnto do so. A fifth and related problem of pure consensualismnis its narrow, desiccated rationalism. By limiting moralnobligations only to those incurred by rational choice, it deniesnthe validity of widespread beliefs that individuals owensomething to their family, community, state, and other socialngroups, and that these groups owe something to their members.nThe reality of these affective attachments calls into questionnthe adequacy of basing obligation on rational consentnalone.nBoth the ascriptive and consent principles are thus attractivenand problematic in their pure forms. It is tempting, then,nto think that the best features of each can be integrated into ancoherent law of citizenship without sacrificing some valuesnthat we cherish. Doubtless, that hope explains why Americannlaw has combined the two and has varied the mix of ascriptivenand consensual elements—especially of birthright citizenshipnand the right of expatriation—over time. But American lawnhas never adequately reconciled these elements; no combinationnof consent or ascription that is either theoretically satisfyingnor practically efficacious, especially in light of currentnconditions, has yet been achieved. For example, two recentnand somewhat related developments have begun to place farngreater strain on the ideological compromises between ascriptionnand consent in America’s citizenship law. The massive increasenin illegal migration to the United States and the equallyndramatic rise of the welfare state have transformed perhapsnthe greatest advantage of birthright citizenship from a modernnliberal viewpoint—its automatic inclusiveness—into somethingnof a disadvantage. By underscoring the growing practicalnimportance of consent as the chief constitutive political principlenof a liberal society, these developments invite us to reconsidernbirthright citizenship on legal and policy as well asnphilosophical grounds. They lead us to reject the traditionalnrule and to propose a more consensualist law of citizenshipnWe may be said to have incurred moralnobligations to illegal aliens by encouraging themnto migrate here, by enriching ourselves throughntheir labor, by absorbing them into ourncommunities, by inviting legitimatenexpectations of humane treatment, and by othernbehavior. But even if moral obligations tonillegal aliens exist and are compelling, they bynno means imply birthright entitlement tonAmerican citizenship.nin which ascribed status at birth plays a correspondingly reducednrole.nWhen the framers of the Fourteenth Amendment’s CitizenshipnClause adopted (in a significantly compromised form)nthe common-law rule of birthright citizenship, immigration tonthe United States was entirely unregulated. In 1980, the numbernof illegal aliens in the United States was conservatively estimatednat between three and a half to six million, with thennumber increasing by two hundred thousand annually. Approximatelyn2 million of these people will eventually receive legalnstatus under the 1986 amnesty law, but many others didnnot qualify or have arrived in the years since 1982, the amnestyncutoff date.nIf mutual consent is the irreducible condition of membershipnin the American polity, questions arise about a practicenthat extends birthright citizenship to the native-born childrennof such illegal aliens. The parents of such children are, byndefinition, individuals whose presence within the jurisdictionnof the United States is prohibited by law and to whom thensociety has explicitly and self-consciously decided to denynmembership. And if the society has refused to consent tontheir membership, it can hardly be said to have consented tonthat of their children who happen to be born while their parentsnare here in violation of American law.nThe present guarantee under American law of automaticnbirthright citizenship to the children of illegal aliens can operate,nat the margin, as one more incentive to illegal migrationnand violation by nonimmigrant (temporary visitor) aliens alreadynhere of their time-limited visa restrictions. When thisnattraction is combined with the powerful lure of the expandednentitlements conferred upon citizen children and theirnnnJULY 1992/23n