Senator Edward M. Kennedy looked skeptically at the federal judge. It was Nov. 15, 2005, and Samuel A. Alito Jr., who was seeking Senate confirmation for his nomination to the Supreme Court, had just assured Mr. Kennedy in a meeting in his Senate office that he respected the legal precedent of Roe v. Wade, the 1973 court decision that legalized abortion.

“I am a believer in precedents,” Judge Alito said, in a recollection the senator recorded and had transcribed in his diary. “People would find I adhere to that.”

In the same conversation, the judge edged further in his assurances on Roe than he did in public. “I recognize there is a right to privacy,” he said, referring to the constitutional foundation of the decision. “I think it’s settled.”

But Mr. Kennedy, a Massachusetts Democrat and longtime supporter of abortion rights, remained dubious that November day that he could trust the conservative judge not to overturn the ruling. He brought up a memo that Judge Alito had written as a lawyer in the Reagan administration Justice Department in 1985, which boasted of his opposition to Roe.

Judge Alito assured Mr. Kennedy that he should not put much stock in the memo. He had been seeking a promotion and wrote what he thought his bosses wanted to hear. “I was a younger person,” Judge Alito said. “I’ve matured a lot.”

The answer did not assuage Mr. Kennedy, who went on to vote against Judge Alito’s confirmation. If the judge could configure his beliefs to get that 1985 promotion, Mr. Kennedy asked in a notation in his diary, how might he dissemble to clinch a lifetime appointment to the nation’s highest court?