John G. Roberts Jr. testified yesterday that he believes that the Constitution protects the right to privacy, the legal underpinning of the nation's landmark abortion law, but he refused to say whether he would vote to uphold Roe v. Wade if he is confirmed as chief justice of the United States.

In a day of sometimes testy exchanges with senators, Roberts distanced himself repeatedly from his conservative writings as a young legal adviser to President Ronald Reagan, including a memo in which he had disparaged privacy as "amorphous" and a "so-called right" not spelled out in the Constitution.

Democrats pressed him aggressively, seeking to elicit his views on abortion and a range of other volatile civil rights issues by reminding him of stances he had advocated in the past. But time and again throughout the first full day of questioning at his Senate confirmation hearing, Roberts refused to divulge the way he would rule on matters of voting rights, gender equity, fair housing and the role of religion in public life.

He deflected some questions by asserting it would be improper to foreshadow his views on cases that might come before the Supreme Court. At other times, he shielded his personal views by saying his early writings simply mirrored the policies of two Republican presidents for whom he worked.

"Senator, I was a staff lawyer; I didn't have a position," Roberts said in a typical exchange, when asked about a memo from the early 1980s advocating a policy that would have allowed colleges to receive federal funds even if some of their programs discriminated against women.

The eight-hour hearing before the Senate Judiciary Committee gave senators their first chance to publicly grill Roberts, 50, nominated by President Bush to succeed the late Chief Justice William H. Rehnquist. Republicans, who control the committee and the full Senate, praised Roberts and defended his refusal to answer questions because the issues they involve could someday come before the high court.

With the political fallout of Hurricane Katrina hovering over the proceedings, amid evidence that poor people and minorities have suffered the most in the disaster, Republicans also sought to portray Bush's nominee as a former lawyer who had at times displayed compassion for the dispossessed.

But Democrats suggested that Roberts might be a stealth nominee who would shift the court more sharply rightward than his careful testimony suggests. They repeatedly read to him his own words from government memos he had written in the 1980s -- excerpts from tens of thousands of documents released in recent weeks from his time as a federal lawyer -- and demanded to know whether they reflected his personal views, then and now.

"His answers are misleading," an exasperated Sen. Joseph R. Biden Jr. (D-Del.) told committee Chairman Arlen Specter (R-Pa.).

"They may be misleading," Specter shot back, "but they are his answers." When the laughter in the marble hearing room died down, Roberts said: "With respect, they are my answers. And, with respect, they're not misleading, they're accurate."

Sen. Lindsey O. Graham (R-S.C.) sought to persuade a reluctant Roberts to say that he would be the ideological heir to Rehnquist, for whom the nominee once worked as a law clerk. Finally, Roberts agreed that his nomination would not lead to "a dramatic departure" from the Rehnquist court.

Specter, who supports abortion rights, and several Democrats challenged Roberts especially hard on his views of Roe, the 1973 decision establishing that women have a constitutional right to privacy that includes the right to an abortion. Because Roe has stood for 32 years, much of the discussion centered on when and why a settled ruling should be overturned.

Roberts told Specter that he respected the doctrine of stare decisis -- letting decided issues stand -- adding, "I do think it is a jolt to the legal system when you overrule a precedent." But some long-standing cases deserve to be overturned, he said, such as those that legalized slavery in the 19th century and racial segregation in the 20th century.

Roberts set forth criteria that he said judges and justices should use to determine whether to "revisit" a precedent, saying they include "settled expectations," the court's legitimacy and whether a precedent is workable or has been "eroded by subsequent developments."

"It is not enough that you may think the prior decision was wrongly decided," said Roberts, who during the 1980s signed a memo saying that Roe was "wrongly decided" and should be overturned.

When Specter asked whether the decision's legal legs have been eroded, Roberts replied: "I feel the need to stay away from a discussion of particular cases."

Later, Biden asked whether "there is a right of privacy to be found in the liberty clause of the 14th Amendment?" Roberts replied, "I do, Senator. I think that the court's expressions, and I think if my reading of the precedent is correct, I think every justice on the court believes that, to some extent or another." The answer appeared ambiguous because some of the current justices have made it clear they would support overturning Roe.

With each senator allotted 30 minutes yesterday to question the nominee, Democrats divided up issues on which they believed Roberts is vulnerable.

Sen. Dianne Feinstein (D-Calif.), the only woman on the panel, cited portions of half a dozen 1980s-era memos by Roberts that she said reflected a lack of support for women's rights. In one of the memos, regarding the nomination for a prize by the Clairol company of a female government lawyer who had been a homemaker before entering law school, he wrote: "Some might question whether encouraging homemakers to become lawyers contributes to the common good, but I suppose that's for the judges to decide."

"I mention these examples to highlight what appears to be either a very acerbic pen or else you really thought that way," Feinstein said. Roberts replied that he has consistently supported "equal rights for women, particularly in the workplace" and said that he had merely been joking with his boss, former White House counsel Fred F. Fielding, "that there are too many lawyers today. . . . It has nothing to do with homemakers."

Roberts, however, did not say whether he currently favors an equal rights amendment or an expansive interpretation of Title IX, a federal law to promote equality for women in higher education -- both of which the Reagan administration opposed.

Feinstein also questioned Roberts, a Roman Catholic who has argued in past writings for an expanded role of religion in public life, about his views on the separation of church and state. "I don't know what that means when you say absolute separation," Roberts replied. "I do know this: that my faith and my religious beliefs do not play a role in judging. When it comes to judging, I look to the law books and always have. I don't look to the Bible or any other religious source."

The panel's senior Democrat, Sen. Edward M. Kennedy (Mass.) challenged Roberts on civil rights, including his memos on voting rights, which reflected Reagan's opposition to broadened federal protections that ultimately were approved by Congress. Roberts responded that the current Voting Rights Act has been found constitutional, saying, "I don't have any issue with that." But he declined to comment on any extension of the law, saying questions about that could come before the court.

Later, Sen. Russell Feingold (D-Wis.) pressed Roberts on why he backed a policy that would have made it harder to prove that states were limiting minorities' voting rights. "I was a 26-year-old staff lawyer," Roberts replied. "I was not shaping administration policy." When Feingold asked whether the policy looked wise in hindsight, the nominee said, "I haven't followed the issue of the particular litigation."

One of the few issues on which Roberts dissented yesterday from Reagan-era policy involved the case of Bob Jones University, in which that administration unsuccessfully argued that the fundamentalist school qualified for federal tax breaks under a law passed by Congress despite its ban on interracial dating. In a 1983 memo, Roberts wrote that the administration "did not feel Congress had given the IRS the authority" to remove the school's tax-exempt status. Yesterday, he told senators he did not believe the Reagan administration had taken "the correct position" on Bob Jones.

Biden accused Roberts of misleading the committee in part by suggesting that his Reagan-era memos simply parroted his superiors' views even though the vigor and detail of the writings suggested the author heartily endorsed them. The senator cited a Feb. 12, 1982, memo in which Roberts defended a Kentucky prison system that provided more services for male inmates than for women. If the system were challenged, the 1982 memo said, Kentucky might end the programs for men, Biden said.

"Explain to me your thinking there," Biden said. Roberts said he did not recall the memo, and when given a copy, he said he was reflecting his boss's views, an example of "good staff work."

"I would regard it as very poor staff work, with all due respect, Judge, because it seems to me you insert your views very strongly in here," Biden said.

Outside the hearing room, Roberts's handling of the abortion issue appeared to frustrate abortion rights proponents, while pleasing antiabortion groups. In front of the Capitol, about a dozen Planned Parenthood Protesters wore shirts emblazoned with the words "Answer the Question." Kate Michelman, the former president of NARAL Pro-Choice America, said, "I don't think we have any clarity yet on his views about Roe and privacy as it relates to reproductive freedom as a fundamental right."

Jay Sekulow of the conservative American Center for Law and Justice said Roberts's description of when courts should be willing to rethink precedents "left the door open" to the possibility he might vote to overturn Roe. "As someone who takes a pro-life position, I was extremely pleased with the answers he gave," he said.

Staff writer Jo Becker contributed to this report.

John G. Roberts Jr. refused to divulge the way he would rule on matters such as voting rights and gender equity. Senate Judiciary Committee Chairman Arlen Specter (R-Pa.), left, and Sen. Patrick J. Leahy (D-Vt.) confer.