Washington ? Chief Justice-nominee John Roberts repeatedly refused to answer questions about abortion and other contentious issues at his confirmation hearing Tuesday, telling frustrated Democrats he would not discuss matters that could come before the Supreme Court.

“I think nominees have to draw the line where they are most comfortable,” said Roberts, who also sidestepped questions about civil rights, voting rights and the limits of presidential power in a long, occasionally antagonistic day in the witness chair.

Appearing before the Senate Judiciary Committee, he said past Supreme Court rulings carry weight, including the Roe v. Wade decision that legalized abortion in 1973. But he quickly balanced that by adding that the same principle allows for overturning rulings, as well.

Over and over, he assured lawmakers he would be guided by his understanding of the facts of cases, the law and the Constitution, not by his personal views.

“My faith and my religious beliefs do not play a role,” added Roberts, who is Catholic.

“I will be my own man,” he said later in a daylong session that Republicans said had firmly established his prospects for swift confirmation.

The 50-year-old appeals court judge and former Reagan administration lawyer fielded questions about dozens of legal precedents without benefit of notes. His wife, Jane Roberts, also an attorney, sat behind him, flanked by a delegation of aides the White Houses assembled to assist him.

Roberts flashed his wit occasionally, announcing with a smile that he had reconsidered his long-ago support for term limits for judges. If confirmed, his appointment will be for life.

In a more serious vein, he disavowed the Reagan administration’s support for a tax exemption for a university that banned racial dating – but also said he hadn’t been involved in discussions on the issue.

Foiling Democrats

He twice rebuffed Democratic attempts to draw him into a discussion of his views on lawsuits under the Voting Rights Act – whether a showing of discrimination should be sufficient to prevail as opposed to a more difficult-to-establish intent to discriminate.

Sen. Arlen Specter, R-Pa., and the committee chairman, raised the question of abortion moments after the hearing began, and the issue reverberated again and again.

“The right to privacy is protected under the Constitution in various ways,” Roberts said at one point. Hours later, he said he agreed with a 38-year-old high court ruling in a case involving contraceptives for married couples, a decision often cited as the underpinning for abortion rights.

He said that if confronted with an abortion case – as seems likely in the high court’s upcoming term – he would give full weight to the precedent of the landmark ruling that established a woman’s right to end her pregnancy.

The legal principle of “stare decisis” requires that, he said – but he also said the same principle allows past rulings to be overturned.

Roberts struck sparks when he indicated his refusal to answer certain questions was based in part on a precedent of “no hints, no forecasts, no previews” that Justice Ruth Bader Ginsburg set at her hearings a dozen years ago.

“That is not true, judge,” interrupted Sen. Joseph Biden, D-Del., telling Roberts that Ginsburg had been far more forthcoming, particularly about abortion.

Specter broke in at that point – one of several times he did so during the day – telling Biden to let Roberts finish his answer.

Biden said Roberts wasn’t answering at all, then said to the witness seated a few feet away: “Go ahead and continue not to answer.”

Despite the Democratic unhappiness, it appeared Roberts’ had done nothing to diminish his strong chances for confirmation to replace the late William H. Rehnquist before the high court convenes on Oct. 3.

“We’re reliving the ’80s,” Sen. Lindsey Graham, R,-S.C., muttered during one break, a reference to numerous questions from Democrats about conservative views Roberts expressed in memos he wrote as a young lawyer in the Reagan administration. Sen. Jeff Sessions, R-Ala., said he was glad Bush had picked Roberts for the job – and happy, too, that the nominee had rebuffed Biden’s questions.

A young chief

If approved, Roberts would become the nation’s 17th chief justice and the youngest in more than 200 years.

President Bush originally named him to replace Sandra Day O’Connor when she announced her retirement earlier this summer. She has been a pivotal vote in recent years on cases that upheld abortion rights and affirmative action, and Roberts is seen by supporters and critics alike as a young, conservative successor with the potential to move the court rightward.

That changed with Rehnquist’s death. Unlike O’Connor, the late chief justice dissented in rulings that upheld a woman’s right to abortion, for example. As a result, some of the intensity seems to have been drained from Roberts’ confirmation proceedings but is likely to resurface when Bush names a new successor to O’Connor.

Matters of opinion

Confronted by Democrats with memos he wrote as a Reagan lawyer, Roberts stepped carefully: “In some instances they were consistent with personal views, in other instances they may not be.”

Roberts sparred briefly with Sen. Edward M. Kennedy, D-Mass., who referred to some of the memos in asking about the views expressed in some that have been made public.

“If your position prevailed, it would have been legal in many cases to discriminate in athletics for girls, women. It would have been legal to discriminate in the hiring of teachers,” Kennedy said.

“You have not accurately represented my opinion,” Roberts replied.

“Those are your words,” Kennedy retorted, but Roberts was unrelenting. “Senator, you did not accurately represent my opinion,” he said.

Sen. Patrick Leahy of Vermont, the senior Democrat on the panel, asked about the limits of presidential power, specifically if the chief executive would be obligated to heed a law calling for the withdrawal of U.S. troops from foreign soil by a fixed date.

“I don’t want to answer a particular hypothetical that could come before the court,” Roberts replied.