"Senator," Roberts retorted, after Sen. Russell D. Feingold, D-Wis., pressed him repeatedly about a particular civil-rights case, "you keep referring to what I supported and what I wanted to do. I was a 26-year-old staff lawyer. It was my first job as a lawyer, after my clerkships. I was not shaping administration policy."

There were similar testy exchanges throughout the day, particularly when the clashes involved civil rights and women's rights. At one point, Roberts pointedly told Sen. Edward M. Kennedy, D-Mass., who has spent 40 years on the committee and who has been a leader in passing civil-rights legislation, that Kennedy had misrepresented his position on a federal anti-discrimination law.

At another point, Sen. Joseph R. Biden Jr., D-Del., accused Roberts of being misleading in answering a question about equal treatment for female prisoners, an accusation the judge firmly denied. Biden repeatedly cut off Roberts, prompting Specter to interject and instruct his Democratic colleague to let the nominee speak.

"He's filibustering, Senator," Biden complained. Then, to Roberts, he said: "Go ahead. Go ahead and continue not to answer."

There were light moments as well, as when Sen. Charles E. Grassley, R-Iowa, read Roberts a lengthy quotation from Benjamin N. Cardozo, the Supreme Court justice in the 1930s, in which the justice remarked that "a judge, even when he is free, is still not wholly free."

Grassley asked what the passage meant and whether Roberts agreed with it.

"I know I agree with it," Roberts responded wryly. "Now let me figure out what he meant by it."

Another humorous moment occurred when Roberts was asked about a 1983 memo in which he advocated term limits for judges.

"You know," he said, "that would be one of those memos that I no longer agree with."

Despite his often-stated reluctance to discuss particular Supreme Court cases, Roberts did not avoid them entirely. He said he agreed with the ruling in Brown v. Board of Education, the 1954 case that declared racial segregation in public schools unconstitutional.

He allowed himself an answer, albeit an artful one, when Sen. Patrick J. Leahy of Vermont, the senior Democrat on the panel, asked about the 1944 case in which the Supreme Court upheld the right of the federal government to place people of Japanese ancestry in internment camps. Leahy asked the nominee whether he would consider such internment unconstitutional.

"I suppose a case like that could come before the court," Roberts replied. "I would be surprised to see it. And I would be surprised if there were any arguments that could support it."