Pledging to be deliberate and thorough, US President George W. Bush said he will select a replacement for Supreme Court Justice Sandra Day O'Connor that "Americans can be proud of."
Conservative and liberal groups quickly vowed a fight over the future of a court closely split on abortion and other social issues.
O'Connor, 75, unexpectedly announced on Friday that she would step down upon Senate confirmation of her successor. Her departure as the first female justice and the decisive swing vote on divisive issues supporting abortion rights and the death penalty gives the court its first vacancy since 1994.
"This is a state of emergency," said Kim Gandy, president of the National Organization for Women. "Every member of the Senate will have to choose sides -- either they will side with the bullies in the Republican leadership or they will take the side of our fundamental freedoms."
Jay Sekulow, chief counsel of the conservative American Center for Law and Justice, countered that the court needs to move away from activists who legislate from the bench.
"There could not be a more significant opportunity for President Bush to impact the direction of the high court," he said.
After waiting more than four years for a chance to strengthen conservatives' influence on the court, Bush was presented with the surprise decision of O'Connor to leave after 24 years. White House officials had anticipated that if anyone retired, it would have been Chief Justice William Rehnquist, 80 years old and ailing with thyroid cancer.
The White House said it would be at least a week before Bush decides. More than a half-dozen candidates are under consideration, an administration official said, and Bush will review names during a trip to Europe beginning Tuesday.
Bush said he will be "deliberate and thorough" in this process.
"The nation deserves, and I will select, a Supreme Court justice that Americans can be proud of," he said. "The nation also deserves a dignified process of confirmation in the United States Senate, characterized by fair treatment, a fair hearing and a fair vote."
Republican Senator Arlen Specter, chairman of the Judiciary Committee that will hold hearings on Bush's candidate, said he doubted there would be a filibuster to delay or block a confirmation vote. Democrats said that was up to Bush.
"Above all, Justice O'Connor has been a voice of reason and moderation on the court," said Senate Democratic leader Harry Reid. "It is vital that she be replaced by someone like her."
O'Connor, a breast cancer survivor, kept her retirement a surprise even from her son. It was not until Friday morning that she dispatched her letter, which was hand-delivered to the president.
Partisans on both sides have been preparing for a vacancy for months. After the news was announced, Senate aides of both parties held strategy meetings.
Officials said they expected the Judiciary Committee to hold hearings three to six weeks after Bush submits a nomination, perhaps beginning next month when Congress is customarily in recess.
O'Connor's decision capped a pioneer's career. President Ronald Reagan broke nearly 200 years of all-male tradition in 1981 when he chose her for the high court.
Aware by her own account of the historical burden, she evolved into a moderate conservative, but more importantly, the consistent center of a fractured court.