Seventh Circuit Judge Richard Posner and his fellow University of Chicago Law School Professor William Landes have authored an article entitled, “Rational Judicial Behavior: A Statistical Study,” which devises a methodology to rank the forty-three Justices who have served on SCOTUS since 1937 from most conservative to least.

Their conclusion?

Four of the five most conservative [J]ustices to serve on the Supreme Court since Franklin Roosevelt [presidential term], including [Justices] Roberts and Alito, are currently sitting on the bench today.


I always find it troubling when commentators (even ones as undeniably accomplished and talented as Judge Posner) attempt to assign political motives (i.e., Legislative or Executive branch motives) to the judiciary because I remain convinced that political labels like “conservative” or “liberal” are ill-suited to describing judicial philosophy. Originalist jurisprudence is not a per se politically conservative concept just as viewing foreign law as persuasive authority is not a direct descendant of politically liberal thought.

Judge Posner and Professor Landes describe how they classified the conservativeness of the Justices by reasoning “[t]hat characteristic is usually proxied by the party of the President who appointed the judge—if it was the Democratic Party the judge is deemed ‘liberal’ and if the Republican Party ‘conservative.'” See Landes, William M. and Posner, Richard A., “Rational Judicial Behavior: A Statistical Study” (April 2008 ) at 2. U of Chicago Law & Economics, Olin Working Paper No. 404 Available at SSRN:

While this may be a seemingly rational way to crudely guess the favored political affiliation of a Justice (particularly in the modern, post-Roe era), one need look no further than Justices Stevens or Souter–both appointed by Republican presidents–for evidence controverting this assumption.

Thx to How Appealing, U.S. News & World Report, and the Legal Theory Blog