The New Median: Ideology in the Post-Kennedy Court

Guest post by Maveric Searle

This week we have a guest blogger, a Northwestern Pritzker law student, Maveric Searle, who developed a new measure of judicial ideology for a final paper in Tonja Jacobi’s Supreme Court cases seminar. He also applied it to the current Term, based on the limited decisions released so far, to answer the very pressing question of who we can expect to be the new median of the Court. Maveric has turned his paper into a ScotusOA post, providing the first take on the new ideological spectrum of the Roberts Court.

A new median

The retirement of Justice Anthony Kennedy in 2018 represented a potentially pivotal moment in the modern history of the Supreme Court. Kennedy had long held the spot of the median justice on the Court. The median justice, whose vote is often the deciding vote in contentious cases, is typically thought of as being the most powerful or the most influential justice. Kennedy’s retirement represented not only the appointment of a new justice, but also the opportunity for a new justice to fill the position at the Court’s center. Chief Justice John Roberts is commonly seen as the favorite to become the new median justice. This post analyzes the Court’s early rulings from the October 2018 Term to see if Roberts has lived up to those expectations, or if the Court’s newest member, Justice Kavanaugh, could be its new median.

Conceiving the Median: Agreeability and Majoritarianism

One simple way to identify the median justice is to look at who has voted in the majority most often this Term. The median justice should have a high rate of voting in the majority because historically the median is in the majority in closely decided cases more often than any other justice.

            The numbers above suggest that the median is likely Kavanaugh or Roberts, each of whom has been in the majority at a higher rate than their colleagues. Kavanaugh has a higher ranking than Roberts, but importantly Kavanaugh did not participate in several cases this term, and a dissenting vote in any one of those cases would have moved him below Roberts.

Another straightforward approach is to look at how often each Justice agreed with the other Justices. The median justice should have a high agreement rate because, by virtue of being centrist, he or she will generally agree with colleagues on either end of the spectrum more often than will the opposite extreme justices.

Once again, Kavanaugh and Roberts are duking it out for top spot, tied for who looks most  likely to be the median in terms of average agreeability rate. Given the similarities in both their rates of voting in the majority and their average agreeability rating, a more sophisticated analysis is needed to determine which of the two is the new median justice.

Ranking the Justices on a Left-Right Ideological Spectrum

It is now well accepted who is a liberal justice and who is a conservative justice, not only because the justices are nominated and confirmed by increasingly polarized political actors, but because each of the currently serving Justices has prior affiliations with either the Federalist Society or the American Constitution Society. The key question is: what are the differences among the liberals and among the conservatives? And in particular, with a new five justice conservative majority, who will be the most moderate conservative justice, and thus the median of the Court?

To identify the median justice by ideology along a left-right continuum, the next measure examines how often each justice votes with the conservative justices as compared to the liberal justices. Justices are classified as liberal or conservative based on the political party of the president who appointed them. It then counts how many liberal and conservative justices each justice agreed with in each case (using the percentage of the ideological bloc that the justice agreed with, to account for the fact that there are more conservative than liberal justices).

In a unanimous decision, every justice would agree with 100% of both the conservative and liberal justices. In a 5-4 ideologically ordered decision, a conservative justice would agree with 100% of the conservative justices and 0% of the liberal justices. In a case like Garza v. Idaho—a 6-3 decision with Thomas, Alito, and Gorsuch dissenting—each justice in the majority agreed with 40% of the conservatives (Roberts and Kavanaugh) and 100% of the liberals. Each justice in the minority agreed with 60% of the conservatives and 0% of the liberals. Justices are given weight for agreeing with themselves to ensure that decisions with a lone dissenter have an impact on the dissenting justice’s final score.

These percentages are then turned into an aggregated 0–1 “liberal score” and an aggregated 0–1 “conservative score,” with e.g. 60% agreement being a score of .6. A net ideology score is then determined by subtracting the liberal score from the conservative score for each justice. Using this method, unanimous decisions do not impact the final score because they result in an equal increase to both the aggregated liberal and the aggregated conservative score.

Finally, the net ideology scores are standardized by taking the final score and dividing it by the number of non-unanimous cases that each justice participated in. This yields a number between -1 and 1 for each justice, who can now be ranked them from left to right.

The resulting ranking lines up well with common intuitions, with the possible exception of Justices Gorsuch and Alito: Gorsuch lying slightly to the left of Alito may surprise some, particularly given Gorsuch’s emphasis on originalism and Alito’s rejection of that methodological approach most commonly associated with conservatism.

However, the scores may be capturing some nuance that would be missed by overly focusing on the two Justices’ rhetorical approaches, as there are some areas where Gorsuch has shown himself to be more liberal than Alito. For instance, in Biestek v. Berryhill, Gorsuch wrote a dissent that was joined by Justice Ginsburg. This dissent likely represents the two formalists agreeing based on factors that were methodological rather than ideological. Given the limited data available from the cases decided so far this Term, an unusual case like Biestek had a significant impact on Gorsuch’s final score: this decision alone moves Gorsuch from slightly to the right of Alito to slightly to the left. But Biestek may be quite representative: when it comes to matters of fairness—a key concept in the standard “underdog”–sympathetic model of liberalism—there is a strong argument to be made that Gorsuch lies to the left of Alito in some areas.

Unlike the statistics on justice agreeability and rate of voting in majority, the standardized ideology scores of Roberts and Kavanaugh demonstrate a significant difference between the two Justices. Although Kavanaugh has been in the majority at the highest rate, and he is tied with Roberts in terms of average agreeability, Roberts’ ideology score puts him distinctly to the left of Kavanaugh.

While it is still early in the post-Kennedy era of the Court, and a number of the Court’s most controversial cases have yet to be decided this term, this method suggests that Chief Justice Roberts will in fact be the Justice to look to as the Court’s new median. The early numbers suggest that we really are seeing “the Roberts Court.”

Who is the Politest Supreme Court Justice?

Politeness takes various forms at SCOTUS oral arguments

Previous work on Supreme Court oral arguments has shown that the female justices are interrupted approximately three times as often as the male justices (see Jacobi & Schweers Justice, Interrupted, updated in a recent post). The same article also showed that over time, the female justices became less polite. At the beginning of their careers, the female justices tend to use polite throat clearing terms such as “I’m sorry,” “excuse me,” “may I ask,” “can I ask,” and saying the advocate’s name. These terms are common to the “female register,” the more polite language typically used by women, but at the Court such politeness offers the opportunity for others to interrupt before the speaker can get to the substance of her question. Over the years, the female justices come down to the lower politeness level at which most of the male justices naturally enter the Court.

It turns out that whether female justices reduce their use of polite language over time depends on what one’s notion of politeness is.  This post takes a more granular look at the issue of politeness with the benefit of additional data.

Click the image to expand

Two Measures of the Politeness of Female Justices

The figure above shows two measures of politeness. First, the blue bars show how often, each justice says “I’m sorry,” “excuse me,” “may I ask,” “can I ask,” or says the advocate’s name (e.g. “Mr. Smith”) as a proportion of how many times the justice spoke. This is the measure used by Jacobi & Schweers. The line of best fit (the dashed line) tracks the trend over time. This confirms the finding women are adapting their behavior, becoming less polite over time in response to the high level of interruptions of female justices.

The second measure, represented by the solid circles connected by the solid lines, also shows the use of polite language but it does not include name-checking the advocate (i.e., saying the advocate’s name when addressing him or her). The solid line shows that there is considerable variation among the female justices in their linguistic patterns. Whereas Justice Sotomayor was relatively low on the more inclusive measure of politeness, she is the most polite in terms of using all of the traditional female register terms, such as “excuse me” and “I’m sorry.”

Furthermore, the female justices do not appear to be reducing the use of this language: the only significant change over time is Justice Sotomayor actually increasing her use of this type of polite language. For the other three female justices, name-checking accounts for the vast majority of Jacobi & Schweers’ concept of politeness. The use of the advocates’ names serves a similar purpose as the other forms of polite language, allowing the speaker to make clear that he or she is interjecting without launching straight into the heart of comment or question; but while it may be polite and serve the same throat clearing function, there does appear to be a difference in the pattern of its use.

Mirror, mirror on the wall, who is the politest of them all?

The next figure shows our different measures of politeness for all justices serving from 1955 through 2017, ranked by their use of polite language. Note that we did not include name-checking by the Chief Justice when introducing the advocate at the beginning of his or her speaking time, since this is an institutional responsibility unique to the Chief. Note also that the estimate for Justice Gorsuch is quite preliminary because he has only served one full Term on the Court. Gorsuch ranks as relatively polite on these metrics, so perhaps his “excruciating[] folksy[ness]” during his confirmation hearing was not just an act. But we note that because it is based on just one year of data, the error term on this estimate is high and Gorsuch’s ranking could change quite significantly in future years.

Click the image to expand

Click the image to expand
Ranking the Politeness of Supreme Court Justices Since 1955

Unsurprisingly, under either measure of politeness, two of the top three most polite speakers are women, who appear in red. Under our broader measure of politeness, on the left, all four women to have served on the Court appear in the top nine. Under the narrower measure of politeness—excluding name-checking the advocate—Justices Ginsburg and O’Connor are demoted from 3rd to 15th, and 5th to 18th, respectively in a field of 33 justices. Either way, with all four women in the top half, this reinforces Jacobi & Schweers’ impression that Justices O’Connor, Ginsburg, Sotomayor, and Kagan are more polite than the average male justice, but the results are more striking with the inclusion of name-checking.

Hail to the Chief?

The difference between the two measures of politeness is dramatically illustrated by Chief Justice Rehnquist. Rehnquist was either the second most polite of all the justices or the fourth least polite, depending on which measure we use. Does the institutional role of the chief justice encourage politeness? The next figure looks more closely at the chief justices, tracking their use of polite language over time.

Click the image to expand

Chief Justices and Politeness Since 1955

Looking just at the totals that the orange bars show, the striking result is the change in Chief Justice Rehnquist’s behavior. When Rehnquist joined the Court in 1972, he was initially very polite but then he quickly settled into a more typical male level of politeness, centering around 0.1 per speech event. Then in 1986, upon being promoted to Chief Justice, he displayed a sudden increase in politeness (as shown by the discontinuity in the dashed line of best fit). At the time, some argued that Rehnquist became more moderate upon taking on his new role, and the historical data support that: his Martin Quinn ideological score went from an extremely conservative 4.18 as Associate Justice to a far more moderate 1.97 as Chief Justice—a massive move toward the center of the Court (about the distance between Justice Thomas and Chief Justice Roberts on the current Court). Our analysis of the oral argument data suggests that Rehnquist may have seen part of his institutional role as Chief to not only be more moderate in voting, but also to be more collegial at oral arguments.

By Tonja Jacobi & Matthew Sag