Updated Segal/Cover Scores

Jeffrey Segal recently updated the Segal/Cover perceived ideology scores by adding Samuel Alito. Alito rates a .1 on a scale that runs from 0 to 1.0, with 0 being the most conservative and 1.0 being the most liberal. The Court now lines up as follows:

    Ginsburg    .680
    Breyer       .475
    Kennedy    .365
    Souter       .325
    Stevens     .250
    Thomas     .150
    Roberts    .120
    Alito          .100
    Scalia        .000

These data and more, including the perceived ideology scores for retired justices from Hugo Black (.875) to Sandra Day O’Connor (.415), can be found at Professor Segal’s website.
 

For the details on this measure, see Lee Epstein & Jeffrey Segal, Advice and Consent 109-111 (Oxford 2005); Jeffrey Segal, Lee Epstein, Charles Cameron, & Harold Spaeth, "Ideological Values and the Votes of U.S. Supreme Court Justices Revisited," 57 Journal of Politics 812-823 (1995); Jeffrey Segal & Albert Cover, "Ideological Values and the Votes of U.S. Supreme Court Justices," 83 American Political Science Review 557-565 (1989).

   

Comments

[Daniel Chapman]

I haven't tracked down the journal article that might explain the methodology yet (a link would be helpful if it's available online), but I question how useful any rating system can be if it precludes the possibility that a justice could ever be more "conservative" than Scalia.

More likely this is just a measure of the personal preferences of whoever made up the numbers. That seems to be the case whenever someone starts talking about "liberal" and "conservative" justices.

I assume they MUST have counted Scalia's vote in Raich as a "conservative" vote... curious.

[Jeff Yates]

I will leave to Jeff Segal a full defense of the scores, but a good starting point for understanding them can be found in the 1989 American Political Science Reveiw article with Cover (available on JSTOR). Very briefly, they are based upon content analysis of newspaper op-ed pieces on the justice from when they were nominated until they got confirmed. Thus, they are derived from the perceptions of the op-ed writers.

Best regards,

Jeff
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Jeff Yates - J.D., Ph.D.
Associate Professor
Department of Political Science
University of Georgia
Athens, GA 30602
Email: jyates@uga.edu
Phone: 706.542.2958
Web: http://www.uga.edu/pol-sci/yates.htm
SSRN page: http://ssrn.com/author=454290
*********************

[Sean Wilson]

Well, we must remember that the scores only explain about 15%-24% of the total voting output of the Court, depending upon whether one models the entire docket or just civil liberties cases (and depending upon how far back you go in history). Indeed, they are not that especially helpful in explaining votes on the merits for the entire docket, let alone sub fields of civil liberties decision making (e.g., core speech, advertising cases, etc).

Indeed (again), the scores tell us that 75-85% of the Court's voting output is due to factors other than newspaper assessments of directionality.

[ohwilleke]

So basically, the scores tell us that the media was very wrong on Stevens and a little wrong on Kennedy before they took office.

[Daniel Chapman]

Now I've read it... I can't believe someone published it. I must remember to cancel my subscription to the "Journal of Politics."

[Sean Wilson]

Truthfully, I would consider career liberal ratings more telling than I would Segal Cover Scores. The newspaper scores are only helpful when they show extreme directionality (as in the case of Alito, for example). This data tells us, for example, that Alito is going to be meaningfully directional (conservative) during his career on the Court. However, two things are evident: (1) if the newspaper assessment is not very extreme, the ratings are not that helpful; and (2) once the real votes start coming in, there is no need to rely upon newspaper guessing. You can just use career directionality as your guide.

[Cornellian]

I don't see how Scalia merits a perfect 000 score after his decision in Raich. How exactly does growing marijuana in your own backyard for your own personal use fall within the scope of the interstate commerce clause? How can a self-proclaimed originalist like Scalia conclude that it does in an opinion that contains not a single reference to original understanding and still have that count as a "conservative" opinion?

That's just one example of many. Compare, for example, his opinion in Lujan v. Defenders of Wildlife, where he thinks up an entirely new constitutional doctrine apparently unnoticed by anyone else since the Constitution's enactment, unsupported by any caselaw and, once again, not a single reference to original understanding.

Thomas is a conservative, at least if "conservative" means "originalist." Scalia is only an originalist when he likes the result that gives him.

[rford]

Note that this is a "perceived ideology score", not a score based on actual ideology or voting patterns. Its whole purpose is to assign a score to how conservative or liberal people *thought* the justice would be. It might be of limited use, but that doesn't mean it's meritless.