The story goes like this:

A delegation of American Jews visited the White House to thank President Theodore Roosevelt for naming Oscar Straus as Secretary of Commerce and Labor—the first Jew ever to serve in the Cabinet. President Roosevelt told the delegation what they wanted to hear: "I chose Oscar Straus because he was the best man for the job irrespective of ancestry and creed!" Everyone applauded.

It fell to the most senior member of the group, Jacob Schiff, to close the meeting. Schiff, very deaf, had failed to hear the president's words. He said: "When the president told me, 'Jake, I vant to put a Jew in the Cabinet, I answered, 'Mr. President, Oscar Straus is the man!"

Ticket-balancing is as American as deep-dish pizza. Nineteenth-century Americans worried about balancing North and South; Yankees, Irish, and Germans. Mid-20th-century Americans shifted the focus to management versus labor and to Catholics, Protestants, and Jews. The man who defined legal liberalism at its zenith, William Brennan, arrived on the Supreme Court not because President Eisenhower liked his rulings but because the Republican ticket wanted to claim credit for appointing an Irish Catholic from a northeastern state.

In this sense, President Obama's desire to appoint a Hispanic woman to the Supreme Court follows tradition. And if Sonia Sotomayor is not exactly a titan of the law, well neither was Lucius Lamar, appointed by President Cleveland in 1887 as the first Southerner to join the court after the Civil War.

But here's the difference between now and then. President Cleveland made no bones about the reason for his appointment. He wanted a Southerner on the court, and Lamar—a former Confederate who had made his peace with the outcome of the war—was the most eligible Southerner for his purposes. There were no condescending statements about ex-Confederates bringing some distinctive perspective to the court because of their life experiences, no insulting insinuation that Southerners somehow felt more empathy than Northerners.

In the early 20th century, firsts were made in a very different way. The first Jew on the Supreme Court, Louis Brandeis, was so obviously outstanding that it was his detractors, not his supporters, who focused on the story of his life. The first African-American, Thurgood Marshall, likewise arrived on the bench after an outstanding career as the chief litigator for the NAACP's desegregation campaigns. Marshall's life story was one of the most eventful and consequential in American history. Yet compared with the impact of his accomplishments, his origins are of secondary interest.

So how is it that Sonia Sotomayor's supporters are putting so much emphasis on her girlhood diabetes and her (very impressive by the way) college transcript?

The answer lies in the complicated set of self-deceptions unleashed by one of the Supreme Court's weirdest rulings, the 1977 case of Bakke v. California.

A California medical school had set aside a quota of admissions slots for black applicants. A rejected white applicant challenged the quota as illegal racial discrimination. The Supreme Court agreed with him and condemned quotas.

At the same time, the Court hesitated to outlaw altogether all racial preferences in favor of minorities. Three hundred years of oppression had left black Americans poorly prepared to walk through the door opened by the end of formal discrimination. In the absence of some kind of preference, it might be another generation, maybe two, before significant numbers of African-Americans qualified for top jobs, top schools, and government contracts. The court could not countenance this result.

So the court offered a compromise. Racial preferences could be permitted if they had a nonracial purpose. In an opinion written by Lewis Powell, the court even helpfully suggested what such a purpose might be. A school might decide, for example, that a racially diverse student body might conduce to the better education of all its students, white and black. In that case, racial preferences would be magically transformed from impermissible discrimination into an educational amenity equally beneficial to all.

Universities, businesses, and governments eagerly clutched this suggestion. That's it! Diversity! We are pursuing diversity!

The echoes of Bakke reverberate in all the advocacy for Sonia Sotomayor. No elected official wants to say: "Look, there are a lot of Hispanics in America. It's about time we had one on the Supreme Court. Sonia Sotomayor looks reasonably adequate. She'll do."

That kind of Tammany Hall talk has no place in Diversity America. Instead, we are told that Sotomayor brings to the court a diverse perspective from which we will all benefit.

This is all flim-flam. In any meaningful sense of the word, nobody gives a damn about "diversity" on the Supreme Court. Does anybody care whether a judge has served in the military or done lawyering for a national security agency? Or whether a judge has expertise in the sciences? Or whether he or she has represented a union as opposed to business clients? Or whether he or she has practiced law abroad or otherwise gained familiarity with foreign legal systems? No, no, no, no. Of all the myriad ways that the life experiences of one lawyer can differ from those of another, it is race and sex that energize our judge-pickers.

Notice something else strange, too: that nobody much cares to prove that a judge's racial background in fact translates into a "diverse" point of view. Sotomayor's supporters point out that the Latina justice has often ruled against plaintiffs alleging racial discrimination. That's very unbiased of her, but it raises a question: If she gives discrimination lawsuits no better shake than any white male judge, then what exactly is the point of her unique experience? Even Sotomayor herself cannot specify any particular way that her judging diverges from anyone else's. In her now famous speech at the University of California in 2001, Sotomayor conceded, "I simply do not know exactly what that difference will be in my judging." But if she cannot identify it, how can she be so very sure it is there?

And does anybody care whether it is there or not? Suppose Sotomayor had a résumé twice as distinguished as her own. Suppose she had excelled as a trial lawyer, or served as head counsel at some great corporation, or published a definitive text on some point of law. Wouldn't that make her a stronger rather than a weaker nominee? Isn't the ideal diversity hire a lawyer who comes from the most vividly hardscrabble background—but in every other respect matches and exceeds the credentials and career of conventionally middle-class lawyers? If so, isn't "diversity" just a euphemism for what is really sought: politically relevant ethnicity?

The closer one looks at it, the more the diversity argument looks like a rationalization, not a reason. Obama chose his judge exactly the way TR chose his Commerce secretary. He offers the same flattering explanation as TR, too. But in TR's day, the audience did not have to pretend to believe the explanation. It says nothing very encouraging about the progress of democracy that now the pretense claims us all.