Washington ? There are about 1.2 million lawyers in the U.S. They learned their craft at 200 American Bar Association-approved law schools, of which the top 20 or so are the most competitive, all with top-notch professors and students.

The Supreme Court poses Sept. 29, 2009, for a portrait at the Supreme Court in Washington. Seated, from left are: Associate Justice Anthony M. Kennedy, Associate Justice John Paul Stevens, Chief Justice John G. Roberts, Associate Justice Antonin Scalia, and Associate Justice Clarence Thomas. Standing, from left are: Associate Justice Samuel Alito Jr., Associate Justice Ruth Bader Ginsburg, Associate Justice Stephen Breyer, and Associate Justice Sonia Sotomayor.

When Justice John Paul Stevens retires this summer, however, the eight remaining members of the Supreme Court — the top arbiter of U.S. law and a check and balance on the White House and Congress — will be composed entirely of legal minds trained at two law schools, Harvard and Yale.

(Justice Ruth Bader Ginsburg earned her law degree from Columbia, another Ivy League school — but only because she left Harvard Law after two years to follow her husband to New York for her final year of study.)

This Harvard-Yale predominance at the pinnacle of justice gives President Barack Obama yet another wrinkle to consider when seeking the best replacement for liberal anchor Stevens, in addition to experience, intellect, age, record, confirmability, gender, race, religion and geographic diversity.

Obama is a Harvard Law graduate, but he also promised to change how Washington works and to bring a greater diversity of Americans into the power structure.

Stevens attended Northwestern, in Chicago, now ranked 11th by U.S. News & World Report. The other seven justices, despite their diverse personal backgrounds, all earned their law degrees from Yale, now ranked No. 1, or from Harvard, No. 2.

Last year, for his first Supreme Court nominee, Obama chose Sonia Sotomayor, a Yale Law grad with an up-by-the-bootstraps life story.

What will guide his decision this time?

Insiders think that Solicitor General Elena Kagan, a Harvard Law alumna and former dean there, is Obama’s most likely pick. She’s well respected, with top credentials. She survived the confirmation process to her current post. She’s not been a judge, so she has no rulings to attack.

Most other names on Obama’s list also studied law at Harvard or Yale, but not all.

Homeland Security Secretary Janet Napolitano, a former Arizona governor and attorney general, earned her J.D. from the University of Virginia (No. 10).

Diane Wood, a federal appeals judge for the 7th Circuit, earned her law degree from the University of Texas at Austin (No. 15).

Leah Ward Sears, former chief justice of the Georgia Supreme Court, earned her law degree from Emory (No. 22) and a Master of Laws from the University of Virginia.

Sheldon Goldman, a political science professor at the University of Massachusetts at Amherst and an expert on the federal judiciary, doesn’t consider the Yale-Harvard predominance on the high court a problem.

He called the concentration of justices from Harvard and Yale, as opposed to other top law schools, “somewhat of a coincidence.”

However, Jonathan Turley, a liberal law scholar at George Washington University (No. 20), disagrees.

Turley said the near-exclusive reliance on Harvard and Yale law grads is “perfectly absurd. … You’re voiding a wide array of interesting and potentially brilliant nominees. It’s like insisting you’re only going to read books by two authors.”