Why Societies Need Dissent
by Cass Sunstein
Harvard University Press, 256 pp., $22.95

YOU MIGHT NOT EXPECT Cass Sunstein's new book to challenge America's mainstream view of judicial selection and partisan politics. After all, its title, "Why Societies Need Dissent," assumes a question that this country answered long ago. After watching the collapse of totalitarian regimes left brittle by the paucity of ideas they tolerated, how many Americans need a book-length explication of why dissent is--in addition to being an inalienable right--a healthy habit for societies to cultivate?

And yet, it would be a mistake to dismiss Sunstein's "Why Societies Need Dissent" as pious, worthy, and unnecessary for us to read. Obvious though much of the book is, one section was playing a role in judicial confirmations a year before the book was even published. At Miguel Estrada's confirmation hearing to be a judge on the D.C. Circuit Court of Appeals, Senator Charles Schumer--one of the nominee's fiercest opponents--offered the following distillation of the data summarized in what is now the eighth chapter:

Professor Cass Sunstein . . . has put together some pretty striking numbers that he will be publishing soon, but he has allowed us to give everyone a sneak peek at today. When you look, say, at the environment cases where industry is challenging pro-environmental rulings, you get some pretty clear results. When they are all Republican panels, industry is proved 80 percent of the time; when they're all Democratic panels, 20 percent of the time. And it's in between when they're two-to-one on either side. If every judge were simply reading the law, following the law, you would not get this kind of disparity. But we know; it's obvious. We don't like to admit it, but it's true that ideology plays a role in this court.

This is a simplistic but not wholly inaccurate summary of Sunstein's work. A respected and sometimes brilliant law professor at the University of Chicago, Sunstein has conducted a study of judicial behavior, and his claims are becoming part of the justification for blocking judges like Estrada, who recently withdrew following a lengthy filibuster. Sunstein argues that judges' ideology (for which party identification serves as a crude but realistic proxy) matters--a lot. Indeed, he claims, ideological voting is rampant "in many controversial areas of the law."

Scholars have sought to demonstrate this before, though few quite as ambitiously. But Sunstein's argument is particularly suited to the current wars over judicial nominations because of a clever wrinkle in the way his data portray the relation between judging and ideology. According to Sunstein, judges are divided by party--but they are unified in their conformity. Indeed, the claim that America's judges are conformists is the chapter's central point: A Republican appeals-court judge sitting with two Democratic judges is likely to vote like the Democrats (and vice versa), while a panel composed of three judges of the same party will tend toward greater ideological extremism than its constituent members might believe individually. In other words, judges' ideology influences not only how those judges vote but how their colleagues vote.