Equality Arguments for Abortion Rights


Roe v. Wade grounds constitutional protections for women’s decision wheth­er to end a pregnancy in the Due Process Clauses.1  But in the four decades since Roe, the U.S. Supreme Court has come to recognize the abortion right as an equality right as well as a liberty right.  In this Essay, we describe some distinctive features of equality arguments for abortion rights.  We then show how, over time, the Court and individual Justices have begun to employ equal­ity arguments in analyzing the constitutionality of abortion restrictions.  These arguments first appear inside of substantive due process case law, and then as claims on the Equal Protection Clause.  Finally, we explain why there may be inde­­­pendent political significance in grounding abortion rights in equality values.

Before proceeding, we offer two important caveats.  First, in this brief Essay we discuss equality arguments that Supreme Court justices have recognized—not arguments that social movement activists made in the years before Roe, that academics made in their wake, or that ordinary Americans might have made then or might make now.  Second, we address, separately, arguments based on the Due Process Clauses and the Equal Protection Clause.  In most respects but one,2 however, we emphasize that a constitutional interpreter’s attention to the social organization of reproduction could play a more important role in de­termining the permissibility of various abortion-restrictive regulations than the particular constitutional clause on which an argument is based.

I. Equality Arguments for Abortion Rights

Equality arguments for abortion rights range widely but share certain core concerns.3  Sex equality arguments ask whether abortion restrictions are shaped solely by the state’s interest in protecting potential life, or whether such laws might also reflect constitutionally suspect judgments about women.  For ex­ample, does the state act consistently to protect potential life outside the abor­tion context, including by offering prenatal care and job protections to women who want to become mothers?  Or is the state selective in protecting potential life?  If so, might abortion restrictions reflect traditional sex-role stereotypes about sex, caregiving, or decision-making around motherhood?4

Equality arguments are also concerned about the gendered impact of abortion restrictions.  Sex equality arguments observe that abortion restrictions deprive women of control over the timing of motherhood and so predictably exacerbate the inequalities in educational, economic, and political life engen­dered by childbearing and childrearing.  Sex equality arguments ask whether, in protecting unborn life, the state has taken steps to ameliorate the effects of compelled motherhood on women, or whether the state has proceeded with indifference to the impact of its actions on women.5  Liberty arguments focus less on these gendered biases and burdens on women.

To be clear, equality arguments do not suppose that restrictions on abor­tio­n are only about women.  Rather, equality arguments are premised on the view that restrictions on abortion may be about both women and the unborn—both and.  Instead of assuming that restrictions on abortion are entirely benign or entirely invidious, equality analysis entertains the possibility that gender stereotypes may shape how the state pursues otherwise benign ends.  The state may protect unborn life in ways it would not, but for stereotypical assumptions about women’s sexual or maternal roles.

For example, the state’s bona fide interest in protecting potential life does not suffice to explain the traditional form of criminal abortion statutes in America.  Such statutes impose the entire burden of coerced childbirth on preg­­nant women and provide little or no material support for new mothers.  In this way, abortion restrictions reflect views about how it is “natural” and appropriate for a woman to respond to a pregnancy.  If abortion restrictions were not prem­ised on these views, legislatures that sought to coerce childbirth in the name of protecting life would bend over backwards to provide material support for the wo­men who are required to bear—too often alone—the awesome physical, emotional, and financial costs of pregnancy, childbirth, and childrearing.6  Only by viewing pregnancy and motherhood as a part of the natural order can a leg­islature dismiss these costs as modest in size and private in nature.  Nothing about a desire to protect fetal life compels or commends this state of affairs.  When abortion restrictions reflect or enforce traditional sex-role stereotypes, equality arguments insist that such restrictions are suspect and may violate the U.S. Constitution.

II. Equality Arguments in Legal Doctrine

While Roe locates the abortion right in the Due Process Clauses, the Supreme Court has since come to conceive of it as an equality right as well as a liberty right.  The Court’s case law now recognizes equality arguments for the abortion right based on the Due Process Clauses.  Additionally, a growing num­ber of justices have asserted equality arguments for the abortion right inde­pendently based on the Equal Protection Clause.

A. Equality Arguments for Abortion Rights and the Due Process Clauses

The modern Court, in unpacking the meaning of the Due Process Clauses in the areas of gay rights and abortion rights, has continuously appealed to equa­lity values.  With respect to gay rights, for example, the Court in Lawrence v. Texas7 wrote that that the petitioners “are entitled to respect for their private lives,” and that “[t]he State cannot demean their existence or control their destiny by making their private sexual conduct a crime.”8  Justice Kennedy fur­ther wrote for the Court that “[e]quality of treatment and the due process right to demand respect for conduct protected by the substantive guarantee of liberty are linked in important respects, and a decision on the latter point advances both interests.”9  Concerns about demeaning, disrespecting, and stigmatizing gay people pervade the Court’s interpretation of the Due Process Clause in Lawrence.10

The Court has also invoked equality concerns to make sense of the Due Process Clauses in the area of abortion rights.  The opinion of the Court in Planned Parenthood of Southeastern Pennsylvania v. Casey11 is shaped to a sub­stantial degree by equality values.  At the very moment in Casey when the Court reaffirms constitutional protection for abortion rights, the Court ex­plains that a pregnant woman’s “suffering is too intimate and personal for the State to insist, without more, upon its own vision of the woman’s role, however dominant that vision has been in the course of our history and our culture.”12  This emphasis on the role autonomy of the pregnant woman reflects the in­fluence of the equal protection sex discrimination cases, which prohibit the government from en­forcing stereotypical roles on women.  Likewise, in the stare decisis passages of Casey, the Court emphasizes, as a reason to reaffirm Roe, that “[t]he ability of women to participate equally in the economic and so­cial life of the Nation has been facilitated by their ability to control their re­productive lives.”13  Here, as elsewhere in Casey, the Court is interpreting the Due Process Clause and draw­ing on equality values in order to make sense of the substance of the right.

The equality reasoning threading through Casey is not mere surplusage.  Equality values help to identify the kinds of restrictions on abortion that are unconstitutional under Casey’s undue burden test.  As the joint opinion applies the test, abortion restrictions that deny women’s equality impose an undue burden on women’s fundamental right to decide whether to become a mother.  Thus, the Casey Court upheld a twenty-four-hour waiting period, but struck down a spousal notification provision that was eerily reminiscent of the com­mon law’s enforcement of a hierarchical relationship between husband and wife.  Just as the law of coverture gave husbands absolute dominion over their wives, so “[a] State may not give to a man the kind of dominion over his wife that parents exercise over their children.”14  An equality-informed understanding of Casey’s undue burden test prohibits government from coercing, manipulating, misleading, or stereotyping pregnant women.

B. Equality Arguments for Abortion Rights and the Equal Protection Clause

The Justices who joined the joint opinion in Casey drew on equality values to interpret the Due Process Clause.  Justices Blackmun and Stevens agreed, making those parts of Casey the opinion of the Court.  But Blackmun’s separate opinion in Casey also appealed directly to the Equal Protection Clause: “By restricting the right to terminate pregnancies,” Justice Blackmun wrote, “the State conscripts women’s bodies into its service, forcing women to continue their pregnancies, suffer the pains of childbirth, and in most instances, provide years of maternal care.”15  And rather than “compensate women for their ser­vices,” Blackmun wrote, the government “assumes that they owe this duty as a matter of course.”16  Blackmun observed that “[t]his assumption—that wo­men can simply be forced to accept the ‘natural’ status and incidents of motherhood—appears to rest upon a conception of women’s role that has triggered the pro­tection of the Equal Protection Clause.”17

This is now an emergent position on the Court.  Writing for four Justices in Gonzales v. Carhart,18 Justice Ginsburg insisted that “legal challenges to un­due restrictions on abortion procedures do not seek to vindicate some gen­eralized notion of privacy; rather, they center on a woman’s autonomy to determine her life’s course, and thus to enjoy equal citizenship stature.”19  Build­ing on Casey’s equality-informed understanding of the Due Process Clause, four justices in Carhart emphasized that freedom from state-imposed roles is fundamental to equal citizenship.  These justices also appealed to key cases in­terpreting the Equal Protection Clause, including United States v. Virginia.20  Writing for the Court in that case, Justice Ginsburg declared that laws differentiating between the sexes require close judicial scrutiny, but al­lowed government to acknowledge sex differences on the condition that sex clas­sifications “not be used, as they once were, to create or perpetuate the legal, social, and economic inferiority of women.”21

In Carhart, Justice Ginsburg invoked equal protection cases—including Virginia—to counter woman-protective arguments for restricting access to abortion, which appear in the majority opinion.  Woman-protective arguments are premised on certain judgments about women’s nature and decisional com­petence.22 But the equal protection precedents that Justice Ginsburg cited are responsive both to woman-protective and to fetal-protective anti-abortion ar­guments.  As Justice Blackmun’s Casey opinion illustrates, equality arguments are concerned that gender assumptions shape abortion restrictions, even when genuine concern about fetal life is present.

C. What About Geduldig?

Equality arguments complement liberty arguments, and are likely to travel together.  There is therefore little reason to reach the abstract question of wheth­er, if Roe and Casey were overruled, courts applying existing equal protection doc­trine would accord constitutional protection to decisions concerning abortion.

That said, it is worth considering whether current equal protection case law supplies an additional framework for recognizing abortion rights.  One commonly cited objection to building an equality framework for abortion rights under the Court’s existing equal protection jurisprudence is the Court’s 1974 decision in Geduldig v. Aiello.23

Proponents of equality arguments have long regarded the state’s reg­ulation of pregnant women as suspect—as potentially involving problems of sex-role stereotyping.  But in one of its early equal protection sex discrimination decisions, the Court reasoned about the regulation of pregnancy in ways not necessarily consistent with this view.  In Geduldig, the Court upheld a California law that provided workers comprehensive disability insurance for all tempo­rarily disabling conditions that might prevent them from working, except preg­nancy.  According to the conventional reading of Geduldig, the Court held categorically that the regulation of pregnancy is never sex based, so that such reg­ulation warrants very deferential scrutiny from the courts.

The conventional wisdom about Geduldig, however, is incorrect.  The Geduldig Court did not hold that governmental regulation of pregnancy never qualifies as a sex classification.  Rather, the Geduldig Court held that governmen­tal regulation of pregnancy does not always qualify as a sex classification.24  The Court acknowledged that “distinctions involving pregnancy” might inflict “an invidious discrimination against the members of one sex or the other.”25  This reference to invidiousness by the Geduldig Court is best understood in the same way that Wendy Williams’s brief in Geduldig used the term “invidious”—namely, as referring to traditional sex-role stereotypes.26  Particularly in light of the Court’s recognition in Nevada Department of Human Resources v. Hibbs27 that pregnant women are routinely subject to sex-role stereotyping,28 Geduldig should be read to say what it actually says, not what most commentators and courts have assumed it to say.

Geduldig was decided at the dawn of the Court’s sex discrimination case law and at the dawn of the Court’s modern substantive due process jurispru­dence.  The risk of traditional sex-role stereotyping and stereotyping around preg­­nancy was developed more fully in later cases, including in twenty-five years of litigation over the Pregnancy Discrimination Act.29  This explains why, when Hibbs was decided in 2003, the Court could reason about pregnancy in ways that the Geduldig Court contemplated in theory but could not register in fact.

III. The Political Authority of the Equal Protection Clause

We have thus far considered the distinctive concerns and grounds of equal­­ity arguments, which enable them to complement liberty arguments for abor­tion rights.  We close by considering some distinctive forms of political authority that equality arguments confer.

Some critics pejoratively refer to certain of the Court’s Due Process deci­sions as recognizing “unenumerated” constitutional rights.  Although there are two Due Process Clauses in the Constitution, these interpreters regard decisions like Roe, Casey, and Lawrence, which recognize substantive rather than pro­cedural due process rights, as lacking a basis in the text of the Constitution, hence as recognizing “unenumerated rights.”

The pejorative “unenumerated rights” is often deployed against Roe and Lawrence in an ad hoc manner, without clarification of whether the critic of unenumerated rights is prepared to abandon all bodies of law that have similar roots or structure.  For example, those who use the objection from unenu­merated rights to attack Roe and Lawrence generally assume that the First Amendment limits state governments; but of course, incorporation of the Bill of Rights against the states is also a feature of the Court’s substantive due process doctrine.30  Other “unenumerated rights” to which most critics of Roe and Lawrence are committed include the applicability of equal protection prin­ciples to the conduct of the federal government.31  And this view cannot readily distinguish other “unenumerated” rights of unquestioned authority, such as the rights to travel (or not),32 marry (or not),33 procreate (or not),34 and use contra­ceptives (or not).35  At their Supreme Court confirmation hearings, Chief Justice Roberts and Justice Alito learned from the experience of Judge Robert Bork by swearing allegiance to Griswold.

But even if the pejorative term “unenumerated” is deployed selectively and inconsistently, it has frequently been deployed in such a way as to affect popular perceptions of Roe’s authority.  Accordingly, in light of criticism of the abortion right as “unenumerated,” it is worth asking whether grounding the right in the Equal Protection Clause, as well as the Due Process Clauses, can enhance the political authority of the right.

Adding claims on the Equal Protection Clause to the due process basis for abortion rights can strengthen the case for those rights in constitutional politics as well as constitutional law.  The Equal Protection Clause is a widely ven­erated constitutional text to which Americans across the political spectrum have long laid claim.  And crucially, once the Supreme Court recognizes that people have a right to engage in certain conduct by virtue of equal citizenship, Americans do not count stripping them of this right as an increase in con­sti­tutional legitimacy.  We cannot think of a precedent for this dynamic.  And so: If the Court were to recognize the abortion right as an equality right, a future Court might be less likely to take this right away.


As we have shown, equality arguments for abortion rights identify a va­riety of constitutional concerns raised by abortion restrictions that liberty arguments may not.  Equality arguments focus on “a woman’s autonomy to determine her life’s course, and thus to enjoy equal citizenship stature.”36

This understanding has increasingly come to shape constitutional law.  We have documented the Supreme Court’s equality-informed understanding of the Due Process Clause in Lawrence and Casey.  We have also identified the grow­ing number of justices who view the Equal Protection Clause as an inde­pendent source of authority for abortion rights.  We view this reading of the substantive due process and equal protection cases as contributing to a synthetic understanding of the constitutional basis of the abortion right—as grounded in both liberty and equality values.  For a variety of reasons this Essay has ex­plored, the synthetic reading leaves abortions right on stronger legal and po­litical footing than a liberty analysis alone.


  1. Roe v. Wade, 410 U.S. 113 (1973).
  2. See infra Part III on the political authority of the Equal Protection Clause.
  3. For examples of work in the equality tradition that emerged in the years before Planned Parenthood of Southeastern Pennsylvania v. Casey, 505 U.S. 833 (1992), see Laurence H. Tribe, American Constitutional Law § 15-10, at 1353–59 (2d ed. 1990); Ruth Bader Ginsburg, Some Thoughts on Autonomy and Equality in Relation to Roe v. Wade, 63 N.C. L. Rev. 375 (1985); Sylvia A. Law, Rethinking Sex and the Constitution, 132 U. Pa. L. Rev. 955 (1984); Catharine A. MacKinnon, Reflections on Sex Equality Under Law, 100 Yale L.J. 1281 (1991); Reva Siegel, Reasoning From the Body: A Historical Perspective on Abortion Regulation and Questions of Equal Protection, 44 Stan. L. Rev. 261 (1992) [hereinafter Siegel, Reasoning From the Body]; and Cass R. Sunstein, Neutrality in Constitutional Law (With Special Reference to Pornography, Abortion, and Surrogacy), 92 Colum. L. Rev. 1 (1992).  For more recent sex equality work, see, for ex­ample, What Roe v. Wade Should Have Said: The Nation’s Top Legal Experts Rewrite America’s Most Controversial Decision (Jack M. Balkin ed., 2005) (sex equality opinions by Jack Balkin, Reva Siegel, and Robin West); and Reva B. Siegel, Sex Equality Arguments for Reproductive Rights: Their Critical Basis and Evolving Constitutional Expression, 56 Emory L.J. 815, 833–34 (2007) [hereinafter Siegel, Sex Equality Arguments for Reproductive Rights] (surveying equality arguments after Casey).
  4. See, e.g., Siegel, Sex Equality Arguments for Reproductive Rights, supra note 3, at 817–22.
  5. See id. at 819.
  6. See generally Siegel, Reasoning From the Body, supra note 3.
  7. 539 U.S. 558 (2003).
  8. Id. at 578.
  9. Id. at 575.
  10. Thus the Court wrote that the very “continuance” of Bowers v. Hardwick, 478 U.S. 186 (1986), “as precedent demeans the lives of homosexual persons.”  Lawrence, 539 U.S. at 575.
  11. 505 U.S. 833 (1992).
  12. Id. at 852.
  13. Id. at 856.
  14. Id. at 898.
  15. Id. at 928 (Blackmun, J., concurring in part, concurring in the judgment in part, and dissenting in part).
  16. Id.
  17. Id.
  18. 550 U.S. 124 (2007).
  19. Id. at 172 (Ginsburg, J., dissenting).  For an argument that “equal citizenship stature” is central to Justice Ginsburg’s constitutional vision, see generally Neil S. Siegel, “Equal Citizenship Stature”: Justice Ginsburg’s Constitutional Vision, 43 New Eng. L. Rev. 799 (2009).
  20. 518 U.S. 515 (1996).
  21. Id. at 534.
  22. See generally Neil S. Siegel, The Virtue of Judicial Statesmanship, 86 Tex. L. Rev. 959, 1014–30 (2008); Reva B. Siegel, Dignity and the Politics of Protection: Abortion Restrictions Under Casey/Carhart, 117 Yale L.J. 1694 (2008).
  23. 417 U.S. 484 (1974).
  24. See Neil S. Siegel & Reva B. Siegel, Pregnancy and Sex Role Stereotyping: From Struck to Carhart, 70 Ohio St. L.J. 1095, 1111–13 (2009); Reva B. Siegel, You’ve Come a Long Way, Baby: Rehnquist’s New Approach to Pregnancy Discrimination in Hibbs, 58 Stan. L. Rev. 1871, 1891–97 (2006).
  25. Geduldig, 417 U.S. at 496–97 n.20.
  26. See Brief for Appellees at 38, Geduldig, 417 U.S. 484 (No. 73-640), 1974 WL 185752, at *38 (“The issue for courts is not whether pregnancy is, in the abstract, sui generis, but whether the legal treatment of pregnancy in various contexts is justified or invidious.  The ‘gross, stereotypical dis­tinc­tions between the sexes’ . . . are at the root of many laws and regulations relating to preg­nancy.” (quoting Frontiero v. Richardson, 411 U.S. 677, 685 (1973))).
  27. 538 U.S. 721 (2003).
  28. Id. at 731 (majority opinion of Rehnquist, C.J.) (asserting that differential workplace leave policies for fathers and mothers “were not attributable to any differential physical needs of men and wo­men, but rather to the pervasive sex-role stereotype that caring for family members is women’s work”); id. at 736 (quoting Congress’s finding that the “prevailing ideology about women’s roles has . . . justified discrimination against women when they are mothers or mothers-to-be” (cita­tion omitted) (internal quotation marks omitted)).
  29. Pregnancy Discrimination Act of 1978, 42 U.S.C. § 2000e(k) (2006) (“The terms ‘because of sex’ or ‘on the basis of sex’ include, but are not limited to, because of or on the basis of preg­nancy, childbirth, or related medical conditions; and women affected by pregnancy, childbirth, or related medical conditions shall be treated the same for all employment-related purposes . . . .”).  Concerns about sex-role stereotyping played a significant part in Congress’s decision to amend Title VIISee, e.g., H.R. Rep. No. 95-948, at 3 (1978) (“[T]he assumption that women will become [pregnant] and leave the labor force leads to the view of women as marginal workers, and is at the root of the discriminatory practices which keep women in low-paying and dead-end jobs.”).
  30. See, e.g., McDonald v. City of Chicago, 130 S. Ct. 3020, 3050 (2010) (Scalia, J., concurring) (“Despite my misgivings about Substantive Due Process as an original matter, I have acquiesced in the Court’s incorporation of certain guarantees in the Bill of Rights ‘because it is both long es­tab­lished and narrowly limited.’”  This case does not require me to reconsider that view, since straightfor­ward application of settled doctrine suffices to decide it.” (quoting Albright v. Oliver, 510 U.S. 266, 275 (1994))).
  31. See Bolling v. Sharpe, 347 U.S. 497 (1954) (holding that de jure school segregation in Washington, D.C. violates the equal protection component of the Due Process Clause of the Fifth Amendment); see also, e.g., Adarand Constructors, Inc. v. Pena, 515 U.S. 200, 240 (1995) (Thomas, J., concurring in part and concurring in the judgment) (“These programs not only raise grave constitutional questions, they also undermine the moral basis of the equal protection principle.  Purchased at the price of immeasurable human suffering, the equal protection principle reflects our Nation’s understanding that such classifications ultimately have a destructive impact on the individual and our society.” (emphasis added)).
  32. See Shapiro v. Thompson, 394 U.S. 618 (1969) (right to travel as a fundamental right).
  33. See Zablocki v. Redhail, 434 U.S. 374 (1978) (right to marry as a fundamental right); Loving v. Virginia, 388 U.S. 1 (1967) (same).
  34. See Skinner v. Oklahoma, 316 U.S. 535 (1942) (right to procreate as a fundamental right).
  35. See Eisenstadt v. Baird, 405 U.S. 438 (1972) (right to contraception for all individuals as a fundamental right); Griswold v. Connecticut, 381 U.S. 479 (1965) (right to contraception for married couples as a fundamental right).
  36. Gonzales v. Carhart, 550 U.S. 124, 172 (2007) (Ginsburg, J., dissenting).

About the Author

Neil S. Siegel is Professor of Law and Political Science, Co-Director, Program in Public Law, Duke Law School. Reva B. Siegel is Nicholas deB. Katzenbach Professor of Law, Yale University.

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