The view that a "personhood" law or a "personhood" amendment to a state constitution would outlaw abortion is widespread among the public.  Furthermore, pro-abortion proponents, and even a trial court judge, claim that legally defining the word "person" to include every human being from the moment of conception would also outlaw or restrict embryonic stem cell research, in vitro fertilization, birth control, and treatment necessary to save a pregnant woman's life.  However, the legal recognition of personhood for a zygote, embryo, or fetus would not outlaw abortion, or anything else, just like legal recognition for an adult does not outlaw the death penalty.

The Constitution does not provide an unconditional right to life to any person.  Moreover, the Constitution does not even mention a right to life.  Consequently, it is important to examine the ways in which life is protected by the Constitution.

To begin, the Constitution contains two provisions that provide absolute protections of life.  Article I, Sections 9 and 10, respectively, prohibit the federal and state governments from passing bills of attainder or ex post facto laws.  For example, a law that designates a specific person for death is a bill of attainder, while a law that increases the punishment for a crime already committed from imprisonment to death is an ex post facto law.

Additionally, the Fifth Amendment contains two clauses that provide express protections of life.  The grand jury clause provides that, ordinarily, a person cannot be tried for an offense that carries the death penalty unless indicted by a grand jury.  The double jeopardy clause provides that, ordinarily, if a person has been tried and either acquitted or convicted and sentenced to imprisonment, the person cannot be tried again for the same offense and sentenced to death.

Otherwise, a federal or state deprivation of life is permissible if the courts, and ultimately, a majority of Supreme Court Justices, decide the deprivation is permissible.  The decisions turn on how the Court, or more specifically, the justices, interpret the Constitution.

Here, the due process clauses of the Fifth and Fourteenth Amendments, which apply to the federal and state governments, respectively, are open to a tremendous amount of judicial interpretation.  According to the Court, the clauses provide two different types of protection: procedural due process, which requires that before depriving a person of life, liberty, or property, the government must follow certain procedures, and substantive due process, which requires that if depriving a person of life, liberty, or property, the government must have sufficient justification.

Moreover, the Court has ruled that the death penalty can be challenged under the Eighth Amendment as cruel and unusual punishment, and the use of deadly force by the police under the Fourth Amendment as an impermissible seizure.

And that is the extent of the Constitution's protection of life.  In contrast, several constitutional provisions, including due process, have the effect of supporting a deprivation of life.

While procedural due process is not involved when the issue concerns the constitutionality of a law, such as the violation of a constitutional right, the concept of substantive due process was invented by the Supreme Court, in part, to protect rights that are not mentioned in the Constitution, and is used in two areas with regard to issues concerning life: to justify the refusal of life-saving medical treatment, and to justify abortion.

Also, the Fourteenth Amendment contains a clause that prohibits the state governments from denying "any person within its jurisdiction the equal protection of the laws."  And the Court has interpreted the Fifth Amendment to apply equal protection to the federal government.

Now, the equal protection clause is used by the Court to evaluate government discrimination and protect fundamental rights.  However, the Constitution is silent on the concept of fundamental rights.  The Court has simply held that some rights are fundamental and require a heightened level of protection from government infringement.  And, on multiple occasions, the Court has broadly interpreted the Constitution to find that a fundamental right exists.  More significantly, the Court has used equal protection, like due process, to justify deprivations of life.

For example, in Eisenstadt v. Baird, the Court found the right to control reproduction, including the right to birth control, under the equal protection clause, while in Roe v. Wade, the Court found the right to abortion under the due process clause.

And in Griswold v. Connecticut, the Court found that a right to privacy exists in several provisions of the Bill of Rights, including the First, Third, Fourth, and Fifth Amendments.  Also, in Griswold, Justice Goldberg used the Ninth Amendment to justify protecting the right to privacy.  Furthermore, the Court can protect fundamental rights under the privileges and immunities clause of Article IV, Section 2, or the privileges or immunities clause of the Fourteenth Amendment.

When the Supreme Court deems that a right is fundamental, the Court usually applies the strict scrutiny test to review a government infringement of the right.  However, the Constitution does not mention the strict scrutiny test, or the alternative tests, applied by the Court.

In fact, the Court has formulated and applied alternative tests in cases involving the same issue.  Moreover, the Court has also used this approach in cases involving the same group -- most notably in cases involving government discrimination against aliens.  Again, there are no provisions in the Constitution that prevent the Court from following this reasoning in other areas.

In sum, the Supreme Court justices have enormous discretion in the interpretation of due process, equal protection, and fundamental rights.  What, then, would be the effect if the Court upheld personhood?

Initially, the legislature of the state that recognized personhood would have the responsibility to pass laws dealing with zygotes, embryos, and fetuses, just like it currently has the responsibility to pass laws dealing with infants, children, adolescents, and adults.  Also, there is a theory that the Fourteenth Amendment allows Congress to define personhood merely by passing a bill, without a constitutional amendment.  Consequently, if Congress defined personhood under the Fourteenth Amendment, and the Court upheld the law, all of the states would have this same responsibility.

Nonetheless, the federal and state governments could still deprive a person of life, or discriminate against a person, prenatal or postnatal.  As explained above, equal protection does not guarantee equal rights: the Court can formulate and apply different tests for evaluating government discrimination in cases involving the same issue and cases involving the same group.  In other words, the legal recognition of personhood would not provide zygotes, embryos, or fetuses with the same legal rights as infants, children, adolescents, and adults.  Indeed, even the latter do not currently have the same legal rights.

Basically, the Supreme Court would have to consider the constitutionality of newly enacted laws dealing with abortion, embryonic stem cell research, in vitro fertilization, birth control, and treatment necessary to save a pregnant woman's life.

Furthermore, if the Court, after upholding personhood, also upheld Roe, a state would then be limited to dealing with prenatal life mostly on issues of tort law and property law.  Again, if Congress defined personhood under the Fourteenth Amendment, this same limitation would then apply to all of the states.

In contrast, the Court could overrule Roe, and uphold a state prohibition of abortion, while also upholding Eisenstadt, and prevent the states from prohibiting birth control, including birth control that has the potential secondary effect of preventing the implantation of an embryo in the uterus after fertilization.  Of course, the result would be that one decision prohibits, while the other permits, the destruction of human life.  But there are no provisions in the Constitution that would prevent the Court from deciding so.

Essentially, in the context of abortion, only a Human Life Amendment to the United States Constitution that overruled Roe while also prohibiting abortion (as opposed to a personhood amendment to a state constitution, or a statute, that merely defined every human being as a person), or a Supreme Court decision that overruled Roe while also prohibiting abortion (perhaps by upholding a personhood amendment to a state constitution that also prohibited the intentional taking of a prenatal person's life, which is a separate issue), would serve the purpose of outlawing abortion without the requirement of additional legislation.

The view that personhood would outlaw abortion stems from two comments: one by Justice Blackmun in Roe, and the other by Justice Stewart during oral arguments.  However, many observations made in Roe are demonstrably incorrect, and the view that personhood somehow provides an unconditional right to life has no basis in constitutional law.  More important, the question to ask is whether the current Supreme Court justices support this view.  The answer, with near certainty, is no.

In Planned Parenthood v. Casey, Justice Scalia, joined by Justice Thomas, wrote that the correct interpretation of the Constitution would put the issue of abortion back to the states, allowing the states to either permit, regulate, or prohibit abortion.

Moreover, in Webster v. Reproductive Health Services, the Court addressed the issue of personhood language in a Missouri statute, and ruled that such language could not be used to regulate or prohibit abortion.  And Justice Scalia concurred in the judgment.

Ultimately, the justices of both the liberal wing and conservative wing of the Supreme Court would have to abandon the constitutional principles and the approaches to constitutional interpretation they have employed their entire careers in order to prohibit abortion, or anything else, solely on the basis of personhood.