It would be naive to think that Justice Souter’s replacement won’t have a major impact on the future of the Supreme Court. At a minimum, if President Obama were to simply hit the refresh button on Justice Souter and replace him with a 55-year old version of himself, the liberal wing of the Court would begin refreshing its aging guard. The Court’s four liberal justices currently have an average age of 76, while the four conservative horseman average only 61.5. Eventually, that conservative majority will be in the same position that the liberal justices are in now and replacing aging liberal justices with young liberal justices gives them a new lease on life.
For better or worse though, President Obama will not be able to replace Justice Souter with an identically-situated clone. While I’m not familiar with any situations in which Justice Souter served a role as what we now consider a “swing vote,” his vote was integral in forging several 5-4 majorities that were not decided along the standard liberal-conservative lines. The most prominent example would probably his position on limiting punative damages in cases like Philip Morris v. Williams (2007) where he lined up with the Chief Justice and Justices Breyer, Alito, and Kennedy to limit the amount of punitive damages that could be leveled upon Philip Morris after they were assessed punitive damages nearly 100 times larger than the compensatory damages.
Just a few weeks ago, the Court decided in Arizona v. Gant (2009) that police officers had limited powers to search the passenger compartment of a car during a routine traffic stop. The case was decided 5-4, but not along the traditional lines. Justice Stevens issued a majority opinion for Justices Scalia, Souter, Thomas, and Ginsburg. Justice Breyer, normally considered a member of the Court’s liberal wing, dissented alongside the Chief Justice and Justices Kennedy and Alito.
The list of cases with non-standard configurations (whatever that means) could go on and on. Last term, the Court decided 5-4 cases along standard lines in only 8 of 12 cases. That leaves a lot of room for Justice Souter’s replacement to significantly alter the trajectory of Constitutional Law in very significant ways.
There are also more subtle changes that Justice Souter’s replacement could signal. People frequently call for a “Justice Scalia-style” Justice, unaware of its real meaning. Despite his enjoyable writing-style, he isn’t nearly as persuasive as people may think. His stubborn adhesion to brightlines and propensity to overturn even recently established precedent has alienated Justice Kennedy on several key issues and there are signs that the Chief Justice, and to a lesser degree Justice Alito, may not be sympathetic to his approach. As Orin Kerr pointed out, there is a reason that a wildly-popular collection of his opinions is called Scalia Dissents.
On a court where several of the most important decisions hinge on the vote of Justice Kennedy, Justice Souter’s replacement could have a very real impact on building consensus for the Court’s liberal agenda. The court hasn’t had a new liberal justice in 15-years and since Justice Breyer’s ascension to the High Court the Court’s liberals may have become ideologically stale. The influx of even a single new ideology could be refreshing for the Court’s liberals and have a significant impact on keeping Justice Kennedy on their side on major issues as well as forging more sturdy majorities in the long-run.