This time each year, thousands of law school graduates retreat into a hermit's existence of 10-hour days, preparing for mind-numbing essays and questions that can trace back to Socrates.

This is the season for the California bar exam - the nastiest entrance test for lawyers in the nation, with a flunk rate that sends shudders through nervous would-be attorneys.

Former Gov. Pete Wilson flunked it, as did current Attorney General Jerry Brown - both after graduating from prestigious law schools.

Even former Stanford University law school Dean Kathleen Sullivan, one of the nation's pre-eminent constitutional scholars, famously flunked a version for practicing attorneys two years ago before surviving it her second time through.

The odds of passing the California bar exam are dismal compared with the rest of the country. In February, the most recent exam results produced an abysmally low pass rate of just 36 percent; the national pass rate in 2006 for all states was 67 percent.

California's rate last July, when most aspiring lawyers take the exam after finishing law school, was 52 percent - above only the District of Columbia and Puerto Rico, according to figures compiled by the National Conference of Bar Examiners.

The carnage after every bar exam isn't leaving the state short on lawyers, by any means. There are still more than 200,000 licensed lawyers in California.

But California's tough bar exam has been a subject of debate for decades and gained renewed attention in 2005 when Sullivan failed what is called the practicing attorneys exam on her first try.

Sullivan, who was already licensed to practice in New York and Massachusetts and had appeared before the U.S. Supreme Court, took the California exam after leaving Stanford and joining a Bay Area law firm.

But the exam for lawyers licensed in other states who want to practice in the California courts is tougher here than elsewhere.

One of the reasons for the low pass rate in California is that the state is one of the few to allow aspiring lawyers to take the exam as many times as they want. California also sets a higher threshold for passing the exam than most other states.

But perhaps the most significant factor in California's hefty rate of flunkers is that it is one of the only states to license lawyers who graduate from law schools that are not accredited by the American Bar Association.

This means anyone who gets their law degree from a correspondence school or law school without ABA credentials can still take the California bar.

Gail Murphy, the state bar's senior executive in charge of admissions, points out that the pass rate in California for students from ABA-accredited law schools isn't much lower than other states.

But Rory Little, a professor at Hastings College of the Law, is more blunt.

"We've got a lot of hack people taking the exam who you really wouldn't want to pass," said Little, whose law school is ABA- accredited. "We've got enough hacks."