In its first case of the 2019 Term, the Supreme Court heard oral argument in Kahler v. Kansas, on the question of whether insanity is constitutionally required to be an available defense to capital murder. Petitioner argued that, in particular, the test of whether a defendant knows right from wrong is constitutionally required, and so Kansas’s consideration of insanity solely as to whether a mental defect prevents the defendant from forming the requisite mens rea, plus consideration at the penalty stage, is inadequate.
One easy way to know that a particular justice is not buying an argument like Petitioner’s is when the justice gives a detailed recitation of the almost always grisly facts of the death penalty case. Justice Alito did just that, reminding everyone that Petitioner Kahler not only killed his estranged wife and her mother, but executed his two daughters in a seemingly premeditated and cruel fashion, telling one to stop crying as he slaughtered her and her family—except for her brother, who had shown more sympathy for their father and so was spared the carnage, if not the trauma. But predicting Justice Alito’s likely vote in death penalty cases is usually pretty easy; predicting some of the other justices’ votes is more difficult, and requires more sophisticated tools. The figure below provides an assessment of the likely votes of each of the justices, based on everything they said at the oral argument, as well as what they have said in every other case they have heard in their time on the Bench.
Like the Supreme Court, ScotusOA took the summer off from empirically analyzing Supreme Court oral arguments. As such, a quick reminder (or an introduction for the uninitiated) is warranted to explain how we generate our predictions. We measure various aspects of each justices’ behavior at a given oral argument, and how that behavior is tilted to one side or the other. We call this the disagreement gap: the difference in the treatment of the two sides is a strong predictor of how the justices will vote. For instance, interrupting one side more or talking more during the time of one side are both strong predictors of ultimately voting in favor of the other side. We then put those variables in the context (using Bayesian updating) of each justice’s behavior in general at oral argument, to create a prediction for each justice, based on their particular style at oral argument generally.
The Kahler oral argument illustrates the value of taking this contextual (Bayesian) approach: Justice Alito was seemingly the strongest advocate for the Respondent’s position—and we use the term “advocacy” advisedly, based on prior research showing that the justices engage in considerable amounts of advocacy during oral argument. Yet, Justice Ginsburg pips him by 1% in her likelihood to vote for Respondent. Now 1% is obviously not statistically significant, but the fact that the liberal Justice Ginsburg is measuring as effectively equally likely as the conservative Justice Alito to vote against a death penalty defendant is significant. This prediction is a product of that aforementioned context: Justice Alito is very often extremely uneven in which side he directs most of his questions and comments to, whereas Justice Ginsburg is very rarely so tilted to one side. In the Kahler oral argument, she only spoke during the time of Petitioner, and that makes us confident that she will vote for Respondent.
A look at the substance of Justice Ginsburg’s questions supports this conclusion. She opened the questioning (after the first application of the new Supreme Court rule that gives advocates two minutes of uninterrupted speaking time) with a tough challenge for Petitioner’s advocate, Sarah Schrup: whether a judgment of “guilty but insane,” which would result in institutionalization rather than imprisonment or the death penalty, would satisfy the Constitution. She followed up with hypothetical variations that prevented Schrup from answering the question by looking to collateral harms, and then Ginsburg asked about whether the history was more complex than Schrup was implying. All of these were indications of her position, but the strongest indication was the fact that she didn’t ask equally tough questions of the other side, as she typically does.
In terms of predicting the case rather than individual justice’s votes, three justices were harder to analyze on the basis of oral argument: the Chief Justice, Justice Kavanaugh, and the perennially silent Justice Thomas. (Thomas was in fact absent due to illness. He will apparently participate in last Monday’s cases on the basis of the briefs and the transcripts.) Thomas is easy to predict in a similar contextual way, but looking at his votes, which overwhelmingly favor the state in death penalty cases. But the two justices most likely to be the median of the Court, Roberts and Kavanaugh, were far more evenhanded than any of the other justices in their questioning and other conduct.
Roberts asked tough questions of both Schrup and Toby Crouse, the advocate for Kansas, but asked nothing of the more persuasive advocate for the government’s side, Elizabeth B. Prelogar, representing the United States. She directly answered the tough questions that Crouse had struggled with—most memorably, Justice Breyer’s question of how Kansas can justify excusing by reason of insanity someone who commits murder because he deliriously thinks his victim is a dog, but executing a person who deliriously believes that a dog commanded him to commit the murder. Prelogar may have satisfied the Chief’s concerns with that side of the argument. Thus, although the numbers show him close to 50:50 but potentially tilting for Petitioner, we predict him more likely to vote for Respondent.
Kavanaugh was more focused on the detail of doctrine and history, and hammered both sides with significant challenges. Whether assessed qualitatively or quantitatively, Kavanaugh’s questions do not reveal his likely vote in this case. Based on the oral argument alone, he really is too close to call. In terms of looking to past opinions, Kavanaugh was not involved in one of the two big death penalty cases last year, Madison v. Alabama. He voted with the conservative majority in the other case, Bucklew v. Precythe, but wrote a separate concurrence emphasizing the narrowness of the opinion—that is, he rode a fine line in the case, and gave little away about his general proclivities in this area. We expect something similar in this case: either a narrow majority opinion in favor of Respondent written by Kavanaugh, or a narrowing concurrence by Kavanaugh.
Petitioner: Breyer, Kagan, Sotomayor
Respondent: Alito, Ginsburg, Gorsuch, Kavanaugh, Roberts, Thomas
Full disclosure: Petitioner’s advocate, Sarah Schrup, is a colleague of Tonja Jacobi’s at Northwestern Pritzker School of Law, and Jacobi helped moot Schrup in preparation for the oral argument.