What's the Point of Diversity on the Supreme Court?

by Conor Clarke

Yesterday's New York Times op-ed page published a bunch of possible confirmation questions for Sonia Sotomayor. Here's one from blogger and law professor Ann Althouse:

If a diverse array of justices is desirable, should we not be concerned that if you are confirmed, six out of the nine justices will be Roman Catholics, or is it somehow wrong to start paying attention to the extreme overrepresentation of Catholicism on the court at the moment when we have our first Hispanic nominee?

Andrew Gelman responds by observing that Catholicism has been historically underrepresented on the Court: "We've had 12 Catholics, 7 Jews, 1 unaffiliated, and 89 Protestants" in the Court's history. (The single unaffiliated justice -- in case you're wondering, as I was -- is David Davis, who was also Lincoln's campaign manager.) But while Gelman's data is interesting, and while I love interesting data, I also think it somewhat misses the point of Althouse's question. As I understand it, her point isn't "let's get rid of the damn Catholics." The point of the question is: "Why do we treat racial diversity as different -- and potentially more desirable -- than other kinds of diversity?" So, why do we?

A good angle into the question might be to think about two different ways you could justify an affirmative action program. One argument would be that affirmative action is needed to correct a lack of opportunity: You might say (indeed, I would say) that certain groups face historic disadvantages that are worth correcting. A second and distinct justification would be that diversity creates social benefits. The usual argument is that diverse classrooms have better discussions, and a diverse officer corps runs a better military, and a diverse business force helps navigate that cliche of an "increasingly globalized world."

But my feeling is that race-based affirmative action works much better under the first justification (creating equal opportunities) than it does under the second (increasing social utility). Why do we think racial diversity -- as opposed to diversity of opinion, religion, sex, sexuality, age, language or class -- is uniquely disposed to make an institution more effective? I also think arguments based on equal opportunity are more effective when you're talking about college admissions than when you're talking about a seat on the Supreme Court. That SCOTUS seat is an outcome, not an opportunity.

And so I sympathize with Althouse's question: Why treat racial diversity as more important than other forms of diversity at a place like the Supreme Court? (I don't think appealing to a large group of voters is a good enough argument!)