Fourteenth Amendment, Section 1:
All persons born or naturalized in the United States, and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside. No State shall make or enforce any law which shall abridge the privileges or immunities of citizens of the United States; nor shall any State deprive any person of life, liberty, or property, without due process of law; nor deny to any person within its jurisdiction the equal protection of the laws.
After wrestling in a number of cases with the question of the permissibility of governmental classifications disadvantaging persons born out of wedlock and the standard for determining which classifications are sustainable, the Court arrived at a standard difficult to state and even more difficult to apply. 1 Although the Court has determined that a person's status as having been born out of wedlock,
is analogous in many respects to the personal characteristics that have been held to be suspect when used as the basis of statutory differentiations, the analogy is
not sufficient to require ‘our most exacting scrutiny.’ The scrutiny to which it is entitled is intermediate,
not a toothless [scrutiny], but somewhere between that accorded race and that accorded ordinary economic classifications. Basically, the standard requires a determination of a legitimate legislative aim and a careful review of how well the classification serves, or
fits, the aim. 2 The common rationale of all the cases involving state action that distinguishes among people based on whether they were born out of wedlock is not clear, is in many respects not wholly consistent, 3 but the theme that seems to be imposed on them by the more recent cases is that so long as the challenged statute does not so structure its conferral of rights, benefits, or detriments so that some children born out of wedlock who would otherwise qualify in terms of the statute’s legitimate purposes are disabled from participation, the imposition of greater burdens upon children born out of wedlock or some classes of children born out of wedlock (e.g., those not acknowledged by their fathers) than upon children born to married parents is permissible. 4
The issue of intestate succession rights for children born out of wedlock has divided the Court over the entire period. At first adverting to the broad power of the states over descent of real property, the Court employed relaxed scrutiny to sustain a law denying children born out of wedlock the right to share equally with children born to married parents in the estate of their common father, who had acknowledged the children born out of wedlock (but not "legitimated" them) and who had died intestate. 5 Labine was strongly disapproved, however, and virtually overruled in Trimble v. Gordon, 6 which found an equal protection violation in a statute allowing children born out of wedlock to inherit by intestate succession from their mothers but from their fathers only if the father had
acknowledged the child and the child had been "legitimated" by the marriage of the parents. The father in Trimble had not acknowledged his child, and had not married the mother, but a court had determined that he was in fact the father and had ordered that he pay child support. Carefully assessing the purposes asserted to be the basis of the statutory scheme, the Court found all but one to be impermissible or inapplicable and that one not served closely enough by the restriction. First, it was impermissible to attempt to influence the conduct of adults not to engage in illicit sexual activities by visiting the consequences upon the offspring. 7 Second, the assertion that the statute mirrored the assumed intent of decedents, in that, knowing of the statute’s operation, they would have acted to counteract it through a will or otherwise, was rejected as unproved and unlikely. 8 Third, the argument that the law presented no insurmountable barrier to children born out of wedlock inheriting since a decedent could have left a will, married the mother, or taken steps to "legitimate" the child, was rejected as inapposite. 9 Fourth, the statute did address a substantial problem, a permissible state interest, presented by the difficulties of proving paternity and avoiding spurious claims. However, the court thought the means adopted, total exclusion, did not approach the
fit necessary between means and ends to survive the scrutiny appropriate to this classification. The state court was criticized for failing
to consider the possibility of a middle ground between the extremes of complete exclusion and case-by-case determination of paternity. For at least some significant categories of children born out of wedlock to intestate men, inheritance rights can be recognized without jeopardizing the orderly settlement of estates or the dependability of titles to property passing under intestacy laws.  10 Because the state law did not follow a reasonable middle ground, it was invalidated.
A reasonable middle ground was discerned, at least by Justice Powell, in Lalli v. Lalli, 11 concerning a statute that permitted children born to married parents to inherit automatically from both their parents, while children born out of wedlock generally could inherit automatically only from their mothers, and could inherit from their intestate fathers only if a court of competent jurisdiction had, during the father’s lifetime, entered an order declaring paternity. The child tendered evidence of paternity, including a notarized document in which the putative father, in consenting to his marriage, referred to him as
my son and several affidavits by persons who stated that the elder Lalli had openly and frequently acknowledged that the younger Lalli was his child. In the prevailing view, the single requirement of entry of a court order during the father’s lifetime declaring the child as his met the
middle ground requirement of Trimble; it was addressed closely and precisely to the substantial state interest of seeing to the orderly disposition of property at death by establishing proof of paternity of children born out of wedlock and avoiding spurious claims against intestate estates. To be sure, some children born out of wedlock who were unquestionably established as children of the decreased would be disqualified because of failure of compliance, but individual fairness is not the test. The test rather is whether the requirement is closely enough related to the interests served to meet the standard of rationality imposed. Also, although the state’s interest could no doubt have been served by permitting other kinds of proof, that too is not the test of the statute’s validity. Hence, the balancing necessitated by the Court’s promulgation of standards in such cases caused it to come to different results on closely related fact patterns, making predictability quite difficult but perhaps manageable. 12
The Court’s difficulty in arriving at predictable results has extended outside the area of descent of property. Thus, a Texas child support law affording children born to married parents a right to judicial action to obtain support from their fathers while not affording the right to children born out of wedlock denied the latter equal protection.
[A] State may not invidiously discriminate against [children born out of wedlock] by denying them substantial benefits accorded children generally. We therefore hold that once a State posits a judicially enforceable right on behalf of children to needed support from their natural fathers there is no constitutionally sufficient justification for denying such an essential right to a child simply because its natural father has not married its mother. 13
Similarly, the Court struck down a federal Social Security provision that made eligible for benefits, because of an insured parent’s disability, all children born to that parent while he or she was married as well as those children born out of wedlock to that parent who were capable of inheriting personal property from the wage-earning parent under state intestacy law; children who were deemed to be born out of wedlock only because of a nonobvious defect in their parents’ marriage; and children born out of wedlock who had been "legitimated" in accordance with state law, but that made other children born out of wedlock eligible only if they were born prior to the onset of disability and if they were dependent upon the parent, or lived with the parent, prior to the onset of disability. The Court deemed the purpose of the benefits to be to aid all children and rejected the argument that the burden on children born out of wedlock was necessary to avoid fraud. 14
However, in a second case, an almost identical program, providing benefits to children of a deceased insured, was sustained because its purpose was found to be to give benefits to children who were dependent upon the deceased parent and the classifications served that purpose. Presumed dependent were all children born to the deceased and his or her spouse while he or she was married children as well as those children born out of wedlock who were able to inherit under state intestacy laws, who were deemed to be born out of wedlock only because of the technical invalidity of the parent’s marriage, who had been acknowledged in writing by the father, who had been declared to be the father’s by a court decision, or who had been held entitled to the father’s support by a court. Children born out of wedlock that were not covered by these presumptions had to establish that they were living with the insured parent or were being supported by him when the parent died. According to the Court, all the presumptions constituted an administrative convenience, which was a permissible device because those children born out of wedlock who were entitled to benefits because they were in fact dependent would receive benefits upon proof of the fact and it was irrelevant that other children not dependent in fact also received benefits. 15