California’s bar exam sets its passing score higher than almost any other state — and it will stay that way for now, the state Supreme Court said Wednesday, despite plunging success rates and complaints that potentially good lawyers are being needlessly screened out.

In a letter signed by all of its justices, the court, which oversees the State Bar and its 261,000 lawyers, said the downward trend appeared to be part of a “broader national pattern” and did not show a need to lower the standards in California.

Only 43 percent of those who took the July 2016 bar exam passed it, the lowest rate in 32 years and lower than the success rates in most other states. The results fueled long-standing protests that the exam’s passing score, the nation’s second highest, was unduly restrictive and tended to reduce the numbers of low-income and minority lawyers.

There is no evidence that the passing score on the California exam “protects the public from unqualified persons practicing law, measures an attorney’s skills or assures attorney competence,” Los Angeles Superior Court Judge Michael Stern said in an opinion column Wednesday in the Daily Journal, a legal newspaper. A less-demanding standard “may contribute to improving the diversity of the legal profession,” he said.

He and other critics proposed lowering the passing grade so that it was closer to the national average. State Bar leaders, torn between opposing sides in the debate, sent the state’s high court a set of alternative proposals to keep the current score or reduce it modestly.

In Wednesday’s letter to the State Bar, the court said the current passing score has been in place since 1987, while passing rates have “risen and fallen over time.” A decline over the past decade mirrors a 9 percent drop in nationwide success rates over the same period, the court said.

The justices said they will consider changing the passing standard in the future, but for now the bar should analyze the exam to see whether changes are needed. The bar, it said, should work with law schools to determine whether changes in instruction methods would raise the scores.

“Examination of these matters could shed light on whether potential improvements in law school admission, education, and graduation standards and in State Bar testing for licensure, combined with effective regulatory oversight of legal education, could raise bar exam pass rates,” the court said. That in turn, it said, would “boost the availability of competent and effective attorneys across all demographics.”

Bob Egelko is a San Francisco Chronicle staff writer. Email: begelko@sfchronicle.com Twitter: @egelko