Justice Sandra Day O'Connor's (search) retirement has been delayed again, putting her at the center of upcoming Supreme Court debates on abortion, the death penalty and gay rights.

Until Thursday, the White House had been pushing to have Harriet Miers (search) confirmed before the court took up some of the most contentious cases of the year. Miers' withdrawal means O'Connor will hear those cases -- and could control the outcome.

She is a moderate who has backed abortion rights and limits on capital punishment. And she has not been hesitant to oppose the Bush administration.

Nearly four months after O'Connor, 75, announced that she was stepping down to care for her ill husband, it's unclear when she will actually retire. She has said she will stay until a successor is confirmed.

She could quit before then, but that is unlikely because it would leave the court with just eight members and the potential for deadlocks.

O'Connor has been hearing cases and voting at closed-door meetings. But if she leaves the court before decisions are announced, her votes will not count.

"She remains the pivotal figure on the court," said David Alistair Yalof, author of a book on Supreme Court vacancies and a University of Connecticut professor.

Justices have already heard one major case, the administration's challenge to Oregon's physician-assisted suicide law, and O'Connor seemed ready to support the law.

On Nov. 30, the justices will review a state abortion law, and on Dec. 6 they will take up an appeal that involves gay rights, as part of a protest against the Pentagon's "don't ask, don't tell" policy. Two death penalty cases are scheduled for Dec. 7.

As long as O'Connor is on the court, she should actively participate in cases, Yalof said.

"It would look bad for the institution if they were manipulating opinions to avoid one of the justice's influence," he said.

O'Connor said in an interview with The Associated Press last month that she was willing to remain "a little longer because of the circumstances that unfolded on the death of our chief justice, which was not anticipated by any of us."

"It's OK," she said of the additional demands, although she made clear that, after 24 years on the Supreme Court, she was looking forward to more time for family and travel.

Until this year, the Supreme Court had no turnover for a record-setting 11 years. Chief Justice William H. Rehnquist died of cancer in September, and President Bush named John Roberts to the job. Before Rehnquist's death, Roberts had been named to succeed O'Connor.

A Senate vote on Miers had been expected in November, so many people thought O'Connor would be on the bench just a few months longer. The court's term began Oct. 3 and runs through the end of June.

"I very much think Sandra Day O'Connor will indeed remain a 'real' justice," said David Garrow, a legal historian at Cambridge University.

O'Connor is a notoriously fast opinion writer, and in the cases that have been argued at the high court this month she has been an energetic questioner.

Her involvement in the abortion case next month would be particularly influential. She is the architect of a 1992 compromise that barred abortion restrictions that impose an "undue burden" on women, and she was expected to be a key vote to strike down New Hampshire's parental notification law. The law lacks an exception allowing a minor to have an abortion to protect her health.