In 20 hours of Senate testimony this week, John G. Roberts Jr. made several comments that would seem reassuring to abortion rights advocates and unsettling to those seeking to outlaw abortion. There is a constitutional right to privacy, he said. And justices should show significant deference to long-settled cases such as the landmark 1973 Roe v. Wade abortion ruling.

But the reaction from both camps in the abortion wars was startling. Abortion rights groups took no comfort in the chief justice nominee's remarks, and antiabortion groups took no offense. The reason, activists on the left and right say, is that both sides vividly remember Clarence Thomas's 1991 confirmation hearing in the same Senate Judiciary Committee room.

Abortion rights groups vilify Thomas, and antiabortion groups hail him, for telling senators he had never discussed or thought about Roe, only to advocate its rejection soon after joining the high court. That 14-year-old hearing echoed so loudly in the Hart Senate Office Building this week that virtually none of the activists seemed willing or able to take Roberts's remarks at face value.

Roe is "settled as a precedent of the court," Roberts told the committee, and is "entitled to respect under principles of stare decisis." The term is Latin for "to stand by that which is decided."

"I do think that it is a jolt to the legal system when you overrule a precedent," Roberts said. "It is not enough that you may think the prior decision was wrongly decided."

Were these not hints that Roberts, if confirmed as chief justice, would be loath to revisit Roe?

Not at all, said Leonard Leo, on leave from the conservative Federalist Society to promote the confirmation effort. "What he said about privacy is, in substance, no different from what other recent nominees have said, . . . Justice Clarence Thomas in particular," Leo said in an interview. And Roberts's discussion of stare decisis, he said, "was almost as though you were having a glimpse into the way a judge would sit in his chambers and do the analysis: . . . Maybe there are times when a jolt in the legal system is acceptable."

Abortion rights groups saw Roberts's testimony in the same light, to their dismay. "While Roberts wanted to give the impression he respected the right to privacy and the precedent of Roe v. Wade, his answers look dangerously similar to the responses Clarence Thomas gave senators during his confirmation hearings," said Nancy Keenan, president of NARAL Pro-Choice America.

Despite such comments, the record shows that Roberts discussed Roe in considerably more detail than did Thomas. Thomas testified that he had never discussed the case, even in private, leaving the impression that he was completely open-minded on the matter. Liberals say Thomas misled the Senate about his strongly antiabortion views and now is awaiting his chance to overturn Roe. Some fear Roberts might do the same.

Roberts left no doubt that he is thoroughly familiar with Roe and the key cases that preceded and followed it. But in the name of judicial impartiality, he refused to say how he would rule if Roe were challenged. That forced senators to focus often on the related issues of privacy -- Roe's legal underpinning -- and stare decisis.

On Wednesday, Sen. Charles E. Schumer (D-N.Y.) cited several cases involving privacy and told Roberts: "It's obvious you will not state where you disagree with Justice Thomas. And it could well be that what he said at his hearing and you said at your hearing might lead you to rule in the same way on privacy." Roberts replied that he believes "there is a right to privacy protected as part of the liberty under the due process clause" of the 14th Amendment.

"Would you say there's a general right to privacy?" Schumer asked. Roberts replied, "I don't know what 'general' means."

His comments chilled liberal groups, including the National Women's Law Center. Its co-president Marcia Greenberger told the committee Thursday: "Like Justice Thomas during his confirmation hearing, Judge Roberts said there is a right to privacy and it applies to the marital relationship and the use of contraceptives, but he refused to say how much further its protections would go."

The conservative Leo took comfort in Roberts's answers. "Schumer pressed him very hard on accepting the word 'general' in the context of right to privacy, and he refused to do so," Leo said. "That says something very meaningful about the way in which he thinks about the right to privacy."

As for the issue of stare decisis and Roe v. Wade's 32 years as the law of the land, Roberts seemed to suggest the ruling is a precedent protected by another precedent: the 1992 Casey v. Planned Parenthood decision affirming Roe. "One way to look at it is that the Casey decision itself, which applies the principles of stare decisis to Roe v. Wade, is itself a precedent of the court entitled to respect," Roberts told Judiciary Committee Chairman Sen. Arlen Specter (R-Pa.). In an interview, University of Richmond law professor Carl Tobias said the nominee seemed to suggest that Roe is "doubly insulated" from reconsideration.

But conservative activists say they are not worried. "What he said about Roe was it's deserving of the respect that every precedent of the Supreme Court gets," said Wendy E. Long, counsel to the Judicial Confirmation Network. "But that's not saying very much. He definitely left the door open to overturning any prior decision, whether it's Roe or something else."

John G. Roberts Jr. finished 20 hours of testimony.