How Public Opinion Influences Judicial Decision Making

By Mike Dorf

As I noted last week, I recently attended a conference on The Judiciary and the Popular Will.  In my earlier post on the conference, I previewed my paper.  Here I'll say a little bit about some of the other papers.

The presenters included a fair number of political scientists and poli-sci-oriented law profs.  Both groups were interested in measuring the size of the effect of public opinion on Supreme Court decision making and the mechanism by which it is transmitted.  Supporting data will come eventually in the published papers, but a preliminary observation is in order: I was surprised by the degree to which the number crunchers found evidence of a direct effect of public opinion on Supreme Court decisions.  I had taken for granted that the chief mechanism by which public opinion influences the Court is judicial appointments: Presidents select and Senates confirm Justices who, broadly speaking, share the public's values.  Nothing I learned at the conference casts doubt on this phenomenon, but substantial evidence was also presented showing that individual Justices are responsive to public opinion over their careers.

Without posting the data and the regressions run, it's hard to make the point precisely.  It's also hard to distinguish between two phenomena: A) Justice X changes her mind on some question because she observes that public attitudes have changed; versus B) Justice Y, as a participant in the same culture as the population as a whole, changes his mind at roughly the same time that the public does.  With an important exception to which I'll return momentarily, rule-of-law values treat A) as highly questionable: judges are supposed to decide cases according to the law, not public opinion.  By contrast, anyone who is remotely realistic will acknowledge that B) is routine.

Now a word on the exception.  Some doctrines expressly take account of public opinion or something related to it.  For example, under the 8th Amendment, a punishment is impermissibly "cruel and unusual" if it offends "the evolving standards of decency that mark the progress of a maturing society."  Thus, we can explain the Supreme Court's decisions in the 1970s--first invalidating the death penalty in Furman v. Georgia and then validating new death penalty statutes in Gregg v. Georgia and companion cases--as a process of self-correction: The Justices thought that society had evolved away from the death penalty, but the legislative reaction to Furman showed that it hadn't, and so the Court adjusted in Gregg.

However, outside the context of legal tests that directly incorporate some notion of public opinion or widely shared values, Justices are quite reluctant to acknowledge a direct role for public opinion.  There may well be one--and some of the examples of quick retreats by the Court or individual Justices, without a change in personnel, strongly suggest that public opinion is directly playing such a role.  So too, a large-n study correlating the liberal-versus-conservative "public mood" with liberal or conservative outcomes tends to support the inference of direct impact on Justices' decisions.  But even there, one could hypothesize instead that the Justices are part of the same mood swing so that rather than reacting to the public change of heart, they simply share it.

Two nice test cases that show how hard it is to tease out the difference between Justices reacting to public opinion and Justices changing their own mind are the two living retired Justices: O'Connor and Souter.  Both Justices O'Connor and Souter became generally more liberal over the course of their respective time on the Court, even as the public mood yo-yo'ed a bit.  Moreover, in much of the same period, other Justices, such as Scalia and Thomas, did not become more liberal.  It is thus hard to attribute the ideological drift of either O'Connor or Souter to broad factors affecting the society as a whole or to micro-shifts in public opinion on particular issues.

At the same time, however, it is by now a commonplace that Justice O'Connor had a knack for reflecting public opinion better even than elected legislators.  Whether that was entirely due to her middle-of-the-road sensibility or a mixture of her own attitude and an eye on public opinion is extraordinarily difficult to figure out.  It's quite likely that Justice O'Connor herself doesn't know.

Thus, I came away from the conference thinking that there is a very large research agenda for someone interested in figuring out how public opinion gets translated into judicial decisions.  I also think that research agenda will be very challenging to pursue.  The political scientists' measures of decided cases--in order to produce statistically significant results--must wash out all sorts of legal and doctrinal nuances that make a large difference in particular cases.  A complete picture of the decision making process in the Supreme Court (or other courts) would require expertise in statistics, law, psychology, and likely several other disciplines.  Whether insights from these fields can be successfully synthesized remains to be seen.