WASHINGTON

About 50 years ago, a young Phoenix lawyer broke the code of silence that is still almost universally observed by former law clerks for Supreme Court justices. The lawyer wanted to sound an alarm.

Most of his fellow clerks, the lawyer said, had been leftists with “extreme solicitude for the claims of Communists and other criminal defendants” and “great sympathy toward any government regulation of business.”

The Phoenix lawyer was William H. Rehnquist, who had clerked for Justice Robert H. Jackson in 1952 and 1953 and who would go on to serve on the Supreme Court for more than 30 years, including 19 as chief justice. In his essay, published in U.S. News & World Report in 1957, he expressed fear that the political views of Supreme Court law clerks were shifting the court to the left.

When his essay provoked an angry response, Mr. Rehnquist retreated, a little. “The resolution of these disagreements,” he wrote in a second U.S. News article, “must await a thorough, impartial study of the matter.”