The composition of the United States Supreme Court—its ideological balance, judicial philosophies, and the personal views of its nine members—exerts a profound influence on the development of constitutional law. Few areas illustrate this dynamic more clearly than the doctrine of incorporation, the process by which the Bill of Rights has been applied to state and local governments through the Fourteenth Amendment. Because incorporation touches on the fundamental rights of every American, shifts in the Court's makeup can produce seismic changes in the scope of liberty. This article examines how Supreme Court composition has shaped incorporation cases, from the early twentieth century to the present, and offers insights that help students and educators understand the intersection of judicial politics and legal interpretation.

The Historical Foundations of Incorporation

The Bill of Rights, ratified in 1791, originally constrained only the federal government. The Supreme Court affirmed this understanding in Barron v. Baltimore (1833), holding that the Fifth Amendment's Takings Clause did not apply to states. The ratification of the Fourteenth Amendment in 1868—with its Privileges or Immunities Clause, Due Process Clause, and Equal Protection Clause—created a constitutional basis for applying Bill of Rights protections against state action. Yet for decades, the Court resisted broad incorporation.

The modern incorporation doctrine began in Gitlow v. New York (1925), where the Supreme Court assumed, without deciding, that the First Amendment's free speech protections applied to states through the Due Process Clause. This case marked the Court's first explicit acknowledgment that the Fourteenth Amendment could "incorporate" provisions of the Bill of Rights. Over the following century, the Court applied most—but not all—of the Bill of Rights to the states through a process known as selective incorporation.

Key milestones include Palko v. Connecticut (1937), where the Court established the "fundamental rights" test: a right must be "implicit in the concept of ordered liberty" to be incorporated. Duncan v. Louisiana (1968) applied the Sixth Amendment right to a jury trial in serious criminal cases. McDonald v. City of Chicago (2010) incorporated the Second Amendment right to keep and bear arms. And Timbs v. Indiana (2019) applied the Eighth Amendment's Excessive Fines Clause to the states. Each of these decisions reflected the ideological composition of the Court at the time of the ruling.

How Supreme Court Composition Shapes Incorporation Decisions

The Supreme Court's ideological balance—often described as conservative, liberal, or moderate—directly influences how justices interpret the Fourteenth Amendment and the scope of incorporated rights. Justices bring distinct judicial philosophies to bear: originalists look to the original public meaning of the Constitution, textualists focus on the plain text, and living constitutionalists view the Constitution as evolving with societal values. These philosophies generate predictable patterns in incorporation cases.

The Impact of Conservative Justices

Conservative justices, particularly those who subscribe to originalism or textualism, tend to approach incorporation cautiously. They emphasize federalism and respect for state sovereignty, arguing that the Fourteenth Amendment was not intended to absorb the entire Bill of Rights. For example, Justice Clarence Thomas has consistently advocated for incorporation through the Privileges or Immunities Clause rather than the Due Process Clause—a more historically grounded but narrower path. In McDonald v. Chicago (2010), Justice Thomas concurred on Privileges or Immunities grounds, while the majority relied on due process. This internal division among conservatives shows how differing originalist theories can produce distinct outcomes.

More recently, the conservative supermajority (as of 2024) has shown willingness to expand incorporation in limited circumstances. In Ramos v. Louisiana (2020), the Court held that the Sixth Amendment requires unanimous jury verdicts for serious crimes, incorporating that rule against the states. Justice Neil Gorsuch, a conservative, wrote the majority opinion, emphasizing the historical and textual basis for the right. Yet in other contexts, such as the Second Amendment, the same conservative majority has been willing to strike down state gun control laws using incorporated rights. This suggests that conservative justices may be more receptive to incorporation when the right in question has deep historical roots and a clear textual basis.

The Impact of Liberal Justices

Liberal justices generally favor broader incorporation, viewing the Bill of Rights as a floor of protections that should be uniformly applied across all states. They tend to embrace the "total incorporation" theory advanced by Justice Hugo Black in the mid-twentieth century, though this theory has never commanded a majority. Instead, liberal justices have supported selective incorporation through expansive readings of the Due Process Clause. In Timbs v. Indiana (2019), a unanimous Court applied the Excessive Fines Clause to the states; Justice Ruth Bader Ginsburg wrote for the Court, and the liberal justices joined without reservation. Similarly, in Obergefell v. Hodges (2015), the Court recognized a fundamental right to same-sex marriage under the Due Process Clause—an example of substantive due process that effectively incorporates a new liberty interest, though not one found in the original Bill of Rights.

Liberal justices are also more willing to expand incorporation to cover rights not explicitly listed in the Bill of Rights, such as the right to privacy or the right to travel. Their decisions often emphasize changing societal norms and the evolving standards of decency that mark a maturing society. When the Court has a liberal majority, incorporation tends to accelerate; when conservatives dominate, the pace slows and the focus shifts to historical validation.

Case Studies: The Role of Composition in Key Incorporation Rulings

Gitlow v. New York (1925): The Opening Door

The Gitlow Court was ideologically mixed, with a conservative-leaning majority that upheld New York's criminal anarchy law. Yet the opinion, written by Justice Edward Sanford, nonetheless assumed that the First Amendment applied to states—a concession that incorporation advocates would later exploit. The outcome shows how even a cautious Court can create precedent that later majorities expand.

Palko v. Connecticut (1937): The Fundamental Rights Test

In Palko, the Court, led by Justice Benjamin Cardozo, upheld Connecticut's double jeopardy law, refusing to incorporate the Fifth Amendment protection against double jeopardy. The decision applied a narrow "fundamental rights" test, reflecting the Court's desire to preserve state autonomy. At the time, the Court included both strong states' rights advocates and New Deal liberals; the compromise preserved a minimalist approach to incorporation.

Duncan v. Louisiana (1968): The Warren Court Expands Rights

The Warren Court, at its height liberal, used Duncan to incorporate the Sixth Amendment jury trial right. Justice Byron White's opinion declared that trial by jury in criminal cases is "fundamental to the American scheme of justice." This ruling, along with other Warren Court incorporation decisions (e.g., Mapp v. Ohio on search and seizure, Gideon v. Wainwright on right to counsel), dramatically reshaped American criminal procedure. The liberal composition was essential to this expansion.

McDonald v. City of Chicago (2010): Incorporation under a Conservative Court

The Roberts Court, with a conservative majority (including Justices Roberts, Alito, Thomas, Scalia, and Kennedy), decided McDonald to incorporate the Second Amendment. Justice Samuel Alito wrote the plurality opinion, relying on the Due Process Clause. The case demonstrates that conservative justices can support incorporation when the right aligns with originalist reasoning and when the historical record supports it. However, the vote was 5–4, with the four liberal justices dissenting (though on method, not on the value of incorporation). This split highlights how ideology drives even the decision to incorporate a right versus the method of incorporation.

Timbs v. Indiana (2019): Unanimity Despite Ideological Divide

In Timbs, the Court unanimously incorporated the Excessive Fines Clause. The opinion, written by Justice Ginsburg, was joined by all justices, including conservatives. This case shows that incorporation can generate consensus when the right is long-established and uncontroversial. However, unanimity is rare; most incorporation cases split along ideological lines when the right in question is politically or culturally contested.

Ramos v. Louisiana (2020): A Conservative Majority Reaches a Liberal Result

In Ramos, a 5–4 decision, the Court incorporated the Sixth Amendment unanimous jury trial requirement. The majority included conservative Justice Gorsuch, who wrote the opinion, along with Justices Thomas (concurring), and the four liberal justices. The four dissenting conservatives (Roberts, Alito, Kavanaugh, Sotomayor—though Sotomayor was in the majority) argued that stare decisis should have preserved Louisiana's non-unanimous jury law. This case exemplifies how conservative justices may vote for incorporation based on original meaning, even if the outcome expands criminal defendants' rights—a result typically associated with liberal jurisprudence. It also shows that the composition of the majority coalition matters as much as the ideological labels.

Broader Implications of Shifting Court Composition

The Supreme Court's composition changes with presidential appointments and retirements. The current Court, with a 6–3 conservative majority, has shown a willingness both to expand and to limit incorporation depending on the right. For instance, in New York State Rifle & Pistol Association v. Bruen (2022), the conservative majority used an incorporated Second Amendment to strike down New York's concealed carry law. On the other hand, the Court has been skeptical of incorporating newer constitutional claims, such as the right to abortion (overturned in Dobbs v. Jackson Women's Health Organization (2022)), which was originally grounded in substantive due process and thus akin to an unenumerated incorporated right.

Looking ahead, cases involving the Eighth Amendment's Cruel and Unusual Punishments Clause, the First Amendment's Establishment Clause, and the Fourth Amendment's exclusionary rule may be revisited as the Court's composition shifts. Students of the Court should monitor how justices appointed by different presidents vote in incorporation cases: originalist conservatives (e.g., Thomas, Gorsuch, and Alito) may protect historically grounded rights, while liberal justices (e.g., Sotomayor, Kagan, and Jackson) may push for broad protections even when the historical record is ambiguous.

External Resources for Further Study

Conclusion

The composition of the Supreme Court is not a static fact; it evolves with each new appointment, and that evolution leaves a clear imprint on incorporation doctrine. From the cautious opening in Gitlow to the expansive protections of the Warren Court, the selective approach of the Burger and Rehnquist Courts, and the originalist turn of the Roberts Court, the arc of incorporation bends according to the ideological and philosophical commitments of the justices. Understanding this relationship allows students and educators to see beyond the black-letter law and appreciate the human and political dimensions of constitutional interpretation. As the Court continues to change, so too will the boundaries of the rights that Americans enjoy against their state governments—a dynamic that makes the study of Supreme Court composition essential for anyone seeking to comprehend the full effect of judicial decision-making on liberty and federalism.