Roe v. Wade relied primarily on the Due Process Clause of the Fourteenth Amendment, which the 1973 Supreme Court read as protecting a right to privacy broad enough to cover a pregnant person’s decision to end a pregnancy.1Library of Congress. Roe v. Wade The Court drew additional support from the Ninth Amendment and from privacy “penumbras” it had identified in other parts of the Bill of Rights, but the constitutional weight rested on that one sentence in the Fourteenth Amendment.
The Due Process Clause of the Fourteenth Amendment
The specific text at the center of Roe is a single line in Section 1 of the Fourteenth Amendment. No state shall “deprive any person of life, liberty, or property, without due process of law.”2Congress.gov. U.S. Constitution – Fourteenth Amendment The amendment was ratified in 1868, primarily to protect the civil rights of formerly enslaved people after the Civil War.3National Archives. 14th Amendment to the U.S. Constitution – Civil Rights 1868 Over the following century, the Supreme Court gradually stretched the meaning of “liberty” in that clause well beyond what the amendment’s framers likely had in mind.
The legal theory doing the work here is called substantive due process. On its face, “due process” sounds procedural: the government must follow fair steps before taking your freedom or property. Substantive due process goes further. It treats certain personal decisions as so fundamental that no procedure, however fair, can justify overriding them. The Roe majority concluded that “liberty” in the Fourteenth Amendment shielded a sphere of bodily autonomy and personal decision-making that included the choice to terminate a pregnancy.4Justia. Roe v. Wade
The Court had already used substantive due process to protect other personal decisions involving the body: the right to refuse life-saving medical treatment, freedom from forced bodily intrusions by police, and the right to choose your own physician. Roe extended that established line of reasoning into reproductive healthcare. The constitutional mechanism was not new. Its application was.
In the Court’s own words, the right to privacy was “founded in the Fourteenth Amendment’s concept of personal liberty and restrictions upon state action,” and it was broad enough to cover a woman’s decision about whether to carry a pregnancy to term.5Legal Information Institute. Abortion and Substantive Due Process That sentence identifies the operative clause. Every abortion case decided over the next five decades turned on how courts read “liberty” in the Fourteenth Amendment.
The Right to Privacy and Griswold’s Penumbras
One problem the Roe Court had to solve: the word “privacy” never appears in the Constitution. The majority got around that gap by building on a theory the Court had introduced eight years earlier in Griswold v. Connecticut, a 1965 case striking down a state law that barred married couples from using contraceptives.6Justia U.S. Supreme Court Center. Griswold v. Connecticut
Justice William O. Douglas, writing for the Griswold majority, argued that several amendments in the Bill of Rights cast “penumbras,” overlapping shadows of protection that together create zones of privacy the government cannot invade without powerful justification. Douglas pointed to five amendments as the source:
- The First Amendment’s protection of association
- The Third Amendment’s ban on quartering soldiers in private homes
- The Fourth Amendment’s guarantee against unreasonable searches
- The Fifth Amendment’s shield against compelled self-incrimination
- The Ninth Amendment’s recognition that the listed rights are not the only ones people hold6Justia U.S. Supreme Court Center. Griswold v. Connecticut
None of those amendments on its own establishes a freestanding privacy right. Taken together, the Griswold Court said, they reveal a constitutional commitment to shielding personal decisions from state intrusion. When Roe applied that reasoning to abortion, it treated the decision to end a pregnancy as falling within those protected zones of personal autonomy. Griswold’s marital-privacy holding became the intellectual bridge to the far more contested terrain of abortion.
The Ninth Amendment’s Supporting Role
The Roe majority looked past the Fourteenth Amendment for reinforcement. The Ninth Amendment reads: “The enumeration in the Constitution, of certain rights, shall not be construed to deny or disparage others retained by the people.”7Constitution Annotated. Ninth Amendment In plain terms: just because the Constitution names certain rights doesn’t mean those are the only rights that exist.
James Madison drafted the amendment to answer a real worry among the framers. Opponents of the Bill of Rights feared that listing specific protections would imply everything left off the list was fair game for government control. The Ninth Amendment closes that loophole, making clear that the people retain rights beyond those spelled out in the text.
In Roe, the Ninth Amendment served as a philosophical backstop rather than the primary legal foundation. The majority used it to reinforce the argument that a right to privacy could exist even without being explicitly named. The Due Process Clause carried the load. The Ninth Amendment answered the predictable objection that the Constitution never mentions abortion or privacy by name.
How the Trimester Framework Applied the Clause
The Court did not treat the liberty interest as absolute. Instead, it built a trimester system that balanced the pregnant person’s protected interest against two state interests that grew stronger as pregnancy progressed: protecting the health of the mother and protecting what the Court called the “potentiality of human life.”1Library of Congress. Roe v. Wade
- First trimester: the abortion decision was left entirely to the woman and her physician. State interests were not yet strong enough to justify interference.1Library of Congress. Roe v. Wade
- Second trimester: the state could regulate abortion in ways reasonably related to protecting the woman’s health, such as requiring properly equipped facilities.
- After viability: the state could prohibit abortion entirely, except when necessary to preserve the life or health of the mother.1Library of Congress. Roe v. Wade
Nineteen years later, Planned Parenthood v. Casey (1992) discarded the rigid trimester structure and replaced it with the “undue burden” standard, while preserving what the Court called Roe’s “central holding”: that states cannot prohibit abortion before fetal viability.8Justia. Planned Parenthood of Southeastern Pa. v. Casey The clause at work did not change. Casey reaffirmed that “liberty” in the Fourteenth Amendment’s Due Process Clause encompassed the abortion decision. Only the test for regulating that liberty was reworked.
The Equal Protection Alternative Roe Didn’t Take
Not everyone agreed that privacy and due process were the strongest constitutional arguments. Justice Ruth Bader Ginsburg was the most prominent internal critic, arguing for decades that Roe should have rested on the Equal Protection Clause of the Fourteenth Amendment rather than the right to privacy.
The Equal Protection Clause sits in the same sentence of the Fourteenth Amendment as the Due Process Clause. It prohibits states from denying “any person within its jurisdiction the equal protection of the laws.”2Congress.gov. U.S. Constitution – Fourteenth Amendment Ginsburg’s reasoning was straightforward: abortion restrictions apply only to people who can become pregnant, and forcing someone to carry a pregnancy has concrete effects on their ability to participate in economic and public life on equal terms. Under this theory, abortion bans perpetuate inequality based on sex by compelling childbearing, a burden that falls on one group alone.
Ginsburg believed that Roe’s reliance on privacy rather than equality left the decision more vulnerable. An equality-based ruling would have forced the Court to confront directly whether pregnancy-specific regulations amount to sex discrimination, a question the privacy framework never required answering. The Roe majority chose a different path. Whether that was a strategic mistake remains one of the most debated questions in constitutional law.
What Dobbs Did to Roe’s Constitutional Foundation
In June 2022, the Supreme Court’s decision in Dobbs v. Jackson Women’s Health Organization overruled both Roe and Casey. The majority wrote: “The Constitution does not confer a right to abortion; Roe and Casey are overruled; and the authority to regulate abortion is returned to the people and their elected representatives.”9Supreme Court of the United States. Dobbs v. Jackson Women’s Health Organization
The Dobbs majority rejected Roe’s entire analytical framework, not just its outcome. The Court applied a test drawn from the 1997 case Washington v. Glucksberg. Under that test, an unenumerated right (one not explicitly listed in the Constitution) receives Due Process Clause protection only if it is “objectively, deeply rooted in this Nation’s history and tradition” and can be described with “careful” specificity.10Library of Congress. Washington v. Glucksberg
Applied to abortion, the majority examined the legal landscape in 1868, when the Fourteenth Amendment was ratified. At that time, three-quarters of the states had criminalized abortion at any stage of pregnancy.11Legal Information Institute. Dobbs v. Jackson Women’s Health Organization 2022 The Court concluded that a right widely treated as a crime when the relevant constitutional provision was adopted could not be “deeply rooted” in American tradition. Under that reasoning, the Due Process Clause simply does not reach abortion.
The Ninth Amendment argument no longer plays a role in federal abortion doctrine. The Equal Protection theory Ginsburg championed never became law. The clause that once protected abortion access nationwide, “liberty” in the Fourteenth Amendment’s Due Process Clause, no longer serves that function after Dobbs. Whether abortion is legal now depends on the law of the state where you happen to live.