By contrast, Chief Justice John Roberts, nominated by President George W. Bush, had served only two years as D.C. Circuit judge.

Second, Judge Sotomayor has sterling educational credentials. She earned a summa cum laude Princeton degree, and the faculty awarded her the Pyne Award given to the student who has earned highest academic honors. She graduated from Yale Law School -- for many, the best law school in the country -- and served as an editor of the Yale Law Journal, a position that only the best students attain on the basis of merit. To have attained these elite educational credentials, Sotomayor had to have been not only book smart, but also socially smart given her humble background.

She relates that when she first arrived at Princeton, which had only recently decided to admit women -- with its eating clubs, Ivy League traditions and tiger mascot -- she thought she had landed on a different planet. Sotomayor learned to bridge the large class and culture divides that plague American life and assimilated quickly into a challenging environment.

Third, Sotomayor will draw upon a wide range of professional experiences. Unlike any justice currently serving on the U.S. Supreme Court, Sotomayor prosecuted murderers, rapists, thieves and drug dealers. This is a "brass knuckles," chaotic, "do-or-die," kind of law practice. Robert Morgenthau, her boss and mentor, reports that "no one pushed around Sonia Sotomayor." She prosecuted the Tarzan Murderer, who entered apartments by climbing down fire escapes, and got a sentence of 75 to life.

By contrast, Chief Justice Roberts spent almost his entire career prior to becoming a judge in the offices of an elite Washington, D.C, law firm, where lawyers work in luxurious office space, enjoy swank lunches, and partners can draw six-figure salaries. Justices Ruth Bader Ginsburg and Antonin Scalia were law professors before they ascended to the Supreme Court.

Fourth, Judge Sotomayor has shown herself to be a smart and moderate judge. She has been overturned fewer times than average in her almost two-decade career as federal judge. The Ricci v. De Stefano white firefighters case, for which she is now being criticized by some, should be viewed as an example of her moderate and prudent approach.

This case is a challenge to the New Haven Fire Department's decision to set aside a test that firefighters had to take to be promoted to the rank of lieutenant and captain.

Upon finding that the test was screening out disproportionate numbers of African American and Latino test-takers for possible promotion, the department re-examined the test, with the help of experts. After administrative hearings, the department decided to set aside the results. The 20 or so white and Latino firefighters, who took the test and had high scores, sued to have the results re-instated under the civil rights anti-discrimination statute.

The district court ruled that this action was not discriminatory, and that the Fire Department, fearing a possible lawsuit acted in accordance with the statute in undertaking a thorough review of its testing procedure to ensure that there was no disproportionate racial impact. The appellate three- judge panel in which Sotomayor participated issued a per curiam opinion, which is not unusual, even in cases of such complexity.

Much has been made of a comment that Sotomayor made at Duke Law School, where she was giving career advice to law students. In a 30-second YouTube, clip she is captured saying that appellate courts are "where policy is made."

But one needs to listen to the full two-minute excerpt to fully understand Sotomayor's point.

She was explaining to law students the choice they had between seeking a prestigious position as a law clerk to an appellate judge or in a lower level trial court. She described trial courts as "seeking to do justice in the individual case ... where facts control," and described practice as "controlled chaos ... jumping from one project to another at a million miles an hour." On the other hand, she said appellate courts are where the "law is percolating ... before the Supreme Court makes a final decision." Appellate judges have to always be thinking of the "next step in the development of the law." She counseled students that public interest firms valued appellate clerking experience more highly than trial court experience.

In the context of legal education this is by no means a radical comment. Describing the judging process as one where judges make policy is a short-hand way of referring to the quandary that professors and law students continuously struggle with throughout three years of law school. For example, the wide latitude that the Supreme Court has in shaping constitutional law. The key words of the 14th Amendment, from which many fundamental rights are derived, are sparse -- "No state ... shall deprive any person of ... due process ... or equal protection of the laws." Given that lack of specificity, constitutional law is by necessity mostly judge-made law, and we acknowledge that upfront in law school. The key question is how to constrain this wide discretion.

Finally, Sotomayor brings two important kinds of diversity to the bench, in life experience and how she would approach judicial decision making.

Sotomayor's life narrative is compelling. During World War II, her parents followed the trek of millions of other Puerto Ricans and emigrated from the Island where unemployment is rampant to New York City to find jobs. Her parents spoke only Spanish. She grew up poor in the Bronx projects, where she had to evade drug pushers on the way to school.

Her mother, upon becoming widowed, worked two jobs to move her family out of the projects.

Justice Samuel Alito stated at his confirmation hearing, "Who I am as a human being and how my background and my experiences have shaped me and brought me to this point ... [are relevant to the confirmation decision] because when a case comes before me involving ... someone who is an immigrant ... I can't help but think of my own ancestors, because it wasn't that long ago when they were in that position. ..." So too, Judge Sotomayor will approach decisions from the perspective, as she once said before another group of students, of a "Latina woman." But that description is incomplete.

She will approach hard decisions with a Princeton-Yale educated brain and the heart of a Puerto Rican woman, who defied all odds to make it out of poverty, and assimilated into the American mainstream through hard work and grit.

That life experience will undoubtedly lead her to have different concerns about the law's future development and ask different questions of lawyers who practice before the Supreme Court than might her white male counterparts, such as Chief Justice Roberts who never faced economic discomfort in his life and never experienced the gritty side of urban life.

The second kind of diversity that Sotomayor will bring to the court is in how she says she will approach hard cases. Sotomayor pledged at the announcement of her nomination that she would always think of the law's impact on the individuals who come to plead justice before the Supreme Court. Here she is heeding the advice of ex-Yale law Dean Anthony Kronman who observed that "to deliberate well ... requires both sympathy and detachment ... good judgment ... [is] marked as much by ... affective dispositions as by intellectual powers." Justice Sandra Day O'Connor, who recently retired, also strived to keep in mind the impact of law on ordinary people's lives.

Under this approach the court's decisions are more likely to be more aligned with the everyday common reality of people's lives. For example, a recent case heard by the Supreme Court must determine whether it is reasonable for school officials to strip search a 13-year old girl when this girl had never had any record of misconduct. This case might make new constitutional law, and the reality of a female teenager who called this "reasonable" search "the most humiliating experience of my life," should figure into whether the school's officials search is deemed reasonable.

Sonia Sotomayor is an excellent choice. If confirmed, the nation will benefit from a new justice who is young and full of vigor, blessed with the common sense learned from life's school of hard knocks, educated in the best schools in the country, able to bridge large cultural and class divides, and shown herself to be compassionate and humble.

Sylvia R. Lazos is the Justice Myron Leavitt professor of law at UNLV's William S. Boyd School of Law.