In recent decades, much progress has been made in diversifying the Supreme Court. While only white males served as justices for more than 175 years, the court now includes three female justices, one Black and one Latina justice.
Despite the increased diversity, however, the court’s voting rules often exclude minority viewpoints.
Like most other courts, the Supreme Court decides its cases by a majority vote. If at least five of the nine justices agree on a resolution, they are able to determine the court’s decision and impose their preferred outcome.
If other justices disagree, they cannot ensure that their views are taken into account by the majority. They can only write a dissenting opinion to express their disagreement with the majority’s decision.
Consider the court’s cases from its 2019-20 term, not including non-controversial 9-0 decisions.
When there were disagreements among the justices, Sotomayor dissented in 44% of cases, according to the news site SCOTUSblog. In those cases, the court’s decisions lacked the perspective of its only minority female member.
Similarly, Thomas also dissented in 44% of cases when the court vote was not unanimous. In those cases, the court’s decisions lacked the perspective of its only minority male member.
No other justice’s voice was excluded as often as were those of Sotomayor and Thomas. And with five white male justices on the court, it’s numerically impossible for the court to render a decision that lacks the perspective of a white male justice.
Single opinions the norm
As a constitutional law scholar who has written extensively about the Supreme Court, I believe there is a ready solution to this exclusion of minority viewpoints. Drawing from the example of jurors and the history of the court between 1801 and 1940, the justices could decide their cases by a unanimous vote.
Criminal juries decide their cases unanimously, and studies demonstrate that, as a result, the majority gives greater consideration to minority viewpoints. Those in the minority participate more in the jury’s deliberations, and their perspectives play a greater role in shaping the jury’s decision.
The Supreme Court also could ensure minority participation by deciding its cases unanimously.
Between 1801 and 1940, the high court generally decided its cases with a single, consensus opinion. As Chief Justice John Marshall recognized in 1801, the court strengthens its authority when it speaks in a unified voice. Hence, he established a norm for the court of consensus decisions.
As Marshall wrote, “The course of every tribunal must necessarily be, that the opinion which is delivered as the opinion of the court, is previously submitted to the judges; and, if any of the reasoning be disapproved, it must be so modified as to receive the approbation of all, before it can be delivered as the opinion of all.”
During Marshall’s first four years as chief justice, all of the court’s opinions were issued for the court as a whole, with just one concurring opinion and no dissenting opinions.
Marshall’s successors maintained this norm of consensus for most of the court’s history. By 1941, only about 8% of cases included a dissenting opinion.
But when Harlan Fiske Stone became chief justice in 1941, he encouraged the expression of dissenting viewpoints. Stone believed that sound principles would result from “the clash of competing and sometimes conflicting ideas.”
Today, one or more justices dissent in more than half of the rulings.
Importantly, when single opinions were the norm, scholars have found that justices on both sides would move toward the other side to reach consensus. Lead justices would shape their drafts to secure broad support from their colleagues. As a result, justices who initially disagreed with the majority were able to join their colleagues in a unanimous decision.
As the legal scholar Robert Post has observed, Chief Justice William Howard Taft “was willing to go to extraordinary lengths to modify his own opinions to reach out to others.”
And even after 1940, justices often recognized the importance of consensus. Perhaps the most famous example occurred in 1954, when Chief Justice Earl Warren was able to forge a unanimous decision in the case of Brown v. Board of Education that struck down segregated schools.
Unanimous decisions are better decisions. No single justice has a monopoly on the perfect legal interpretation – they all have their blind spots. The collective wisdom of the full bench is superior to that of a mere majority of justices.
Empirical research on group decisions confirms this.
As one important study found in 1996, “Heterogeneous groups outperform homogeneous groups on tasks requiring creative problem solving and innovation, because the expression of alternative perspectives can lead to novel insights.”
When people with different perspectives make decisions together, they can identify solutions that none of them acting alone would have recognized. Their different ideas can combine to identify new approaches that better serve the public interest.
Majority voting allows for decisions based on a narrower rather than broader range of perspectives. It is incoherent to value a diversity of perspectives and then employ a decision-making rule that frequently disregards an important part of that diversity. This is especially the case when the Supreme Court can decide critical issues by a 5-4 margin.
By restoring a norm of unanimous decisions, the Supreme Court would give voice to all of its justices and the unique perspectives that each of them brings.
As Chief Justice John Roberts has observed, “The rule of law benefits from a broader agreement.”