Meet the New Pivotal Justice on the Supreme Court: John Roberts

Associate Justice Anthony Kennedy’s retirement from the Supreme Court is a huge deal. Although perhaps not quite as huge as some anticipate.

Kennedy’s replacement will almost certainly have a bigger single impact on the Court relative to Scalia’s replacement (Neil Gorsuch) because Gorsuch’s appointment did not change the median voter on the Court. Kennedy has been the “median voter” among the nine justices on a number of different issues. That means for 5-4 decisions on those cases, his vote effectively decides which side wins the case and which side loses.

If, as likely, President Trump appoints a new associate justice somewhere in the legal/ideological neighborhood of his other nominee, Gorsuch, and the Senate confirms the nominee, the Court will naturally move to the right. But the distance it moves to the right will not be the distance between Kennedy’s position on cases and the new justice’s position on cases. Rather, the Court will move to the right only to the point of the new median justice. This is almost certainly Chief Justice John Roberts.

Lining up the justices on a legal/ideological spectrum from left to right would seem to provide this ranking, from most liberal to most conservative: Sotomayor, Ginsburg, Kagan, Breyer, Kennedy, Roberts, Alito, Gorsuch, and Thomas. Kennedy is the ideologically median voter, so he is the pivotal justice on many cases.

No matter how conservative the next justice Trump appoints, the furthest the Court will move to the right is to Roberts’ position. If Trump appoints anyone to the right of Roberts, it would not move the Court’s decisions any further right. At least it would not move the Court any further to the right than Roberts, absent a couple of possibilities. Before discussing those possibilities, however, it’s important to note that Roberts’ positions on the many legal and constitutional issues are likely to be significantly more conservative than Kennedy’s position, that it could provide different outcomes on some of the most controversial issues litigated in the last generation than those that prevailed with Kennedy as the median vote.

Before conservatives count their chickens, however, there is a significant doctrinal issue that cuts orthogonally across the legal/ideological spectrum. An issue we need to learn concerning the position of the five conservative justices (assuming Trump’s nominee is confirmed): To what extent any of the five conservative justices might defer to precedent despite believing an original case was wrong decided. Conservatives cannot ignore the ghost of Casey, and the pull precedent might have on one or more conservative justices.

To the extent that even one of the conservative justices values precedent independent of a belief that a case was wrongly decided originally, then the possibility exists some earlier decisions will be ratified rather than overturned, despite the fact those cases would be differently decided by the new Court if it were to have decided the case as an original matter. Only one conservative defection on the basis of precedence on any earlier decision, including the most controversial ones, means that the Court will not in fact move right on those issues.

At the same time, there is the possibility the Court will move further to the right than Roberts’ current position. The possibilities here are twofold. The first is that Roberts has been voting strategically on (some) important cases to develop some common space in which to negotiate with the more liberal justices. If that has been Roberts’ game, there might be preliminary evidence of it starting to work. Particularly after this term, there is already some criticism on the left about Justice Kagan “drifting” to the right.

A second possibility is that a persuasive new justice might persuade Roberts to move further to the right than he is now, even if he has been voting non-strategically in cases up to now. This does not happen a lot. Scalia is the poster child for this possibility, at least on the issue of statutory interpretation. Before Scalia was on the Court, justices would regularly cite legislative history in their opinions on decisions pertaining to statutory interpretation. After Scalia’s appointment, and his crusade to prefer the authority of legislative text over legislative history, justices cited legislative history far less frequently.

Unless Trump does the unlikely, and appoints a justice around Kennedy’s position, then, unlike Gorsuch’s appointment, this next appointment will have a dramatic impact on Supreme Court decisions. How dramatic that impact, however, does not depend on the appointee himself or herself, but depends more on how Chief Justice Roberts wants to decide cases going forward. He will almost certainly be the new median justice on the Supreme Court.