The Bush administration withdrew the Supreme Court nomination of White House Counsel Harriet Miers yesterday, bowing to intensifying attacks from right-leaning activists challenging the depth of her conservative credentials and the strength of her judicial qualifications.

The decision was sealed in a phone call between Miers and President Bush on Wednesday night, and it abruptly reopened the search for a successor to the pivotal seat held by retiring Justice Sandra Day O'Connor. Bush said he will name a new candidate in a "timely manner," and some in the White House are pushing for a nomination perhaps as soon as today.

Miers's withdrawal touched off a fresh wave of speculation about whom Bush would nominate for the seat. Some conservative activists predict Bush will reconsider some previously thought to be in the running, including federal appellate judges Samuel A. Alito Jr., J. Michael Luttig, Karen J. Williams, Michael W. McConnell and Priscilla R. Owen. Another federal judge mentioned is Diane S. Sykes.

Others speculated that Bush might nominate a senator with judicial experience, such as John Cornyn (R-Tex.), to avoid a contentious battle because senators would be unlikely to reject one of their own. Cornyn, a former Texas Supreme Court justice and one of the few to actively back Miers, played down that possibility, saying: "I doubt it will happen."

The debacle of Miers's nomination comes amid the possible indictments of senior White House advisers in the CIA leak investigation and growing public restiveness over the war in Iraq. Republicans say the president's selection must placate conservatives, reassert his control over the selection process and meet Senate approval.

The White House was tight-lipped about the possible nominees, but some advocacy groups that had pushed for Miers's withdrawal made clear they expect a nominee with an unmistakable record as a judicial conservative.

"We are assured that the president will keep his promise to nominate a strict constructionist," said Jan LaRue, chief counsel of Concerned Women for America, which opposed Miers. Although Miers is an evangelical Christian, the group nonetheless accused her of supporting people and groups who "undermine respect for life and family."

Senate Democrats, meanwhile, called on Bush to name a consensus candidate, while chastising him for giving in to the demands of conservative activists. "The radical right wing of the Republican Party killed the Harriet Miers nomination," said Minority Leader Harry M. Reid (Nev.), who had recommended that Bush consider her for the high court. "Apparently, Ms. Miers did not satisfy those who would pack the court with rigid ideologues."

In announcing the decision, Miers and Bush cited their concern with requests from members of the Senate Judiciary Committee for documents dealing with her work as White House counsel -- papers that the administration has withheld as privileged. Senators sought documents that might illuminate her legal views.

"Protection of the prerogatives of the executive branch and continued pursuit of my nomination are in tension," Miers said in a withdrawal letter she hand-delivered to Bush yesterday. "I have decided that my confirmation should yield."

In a statement, Bush said he reluctantly accepted Miers's withdrawal, even as he praised her as an extraordinary lawyer and a pioneer in expanding women's role in the law. He said disclosure of internal documents detailing the advice Miers gave him during five years as a White House staff member "would undermine a president's ability to receive candid counsel."

Bush added that Miers will remain White House counsel, in which her responsibilities include vetting judicial nominees and helping prepare them for the confirmation process.

The nomination of Miers, 60, to be the nation's 110th Supreme Court justice was imperiled almost from the beginning. Miers was a top-shelf corporate lawyer who spent three decades breaking down barriers in the male-dominated Texas legal establishment. But her candidacy encountered immediate criticism because of her lack of judicial experience and constitutional background, and her close relationship with Bush.

Democrats accused of her of being a Bush crony, because she had served as his personal lawyer in Texas before providing legal advice to his two gubernatorial campaigns and then serving on his White House staff. Many conservative activists, meanwhile, were appalled that Bush passed over a deep roster of doctrinaire conservative jurists in favor of a candidate with a sparse legal paper trail and no known record as a constitutional thinker.

Those objections only sharpened in the weeks since her Oct. 3 nomination. Miers's speeches and writings during her short stint as a member of the Dallas City Council and as a bar association leader in Texas in the 1990s suggested that she harbored liberal sentiments on some issues, such as affirmative action, and inconsistent views on other social issues, such as abortion.

With the ideological balance of the Supreme Court at stake with the retirement of O'Connor -- who has often been a swing vote -- many conservative groups decided to openly challenge the president by opposing Miers. Right-leaning columnists called for her withdrawal, and earlier this week two conservative coalitions launched a campaign that included plans for radio and television ads calling on her to step down.

On Capitol Hill, senators had been raising pointed questions about Miers's legal views and experience. In a letter to Miers on Wednesday, Judiciary Committee Chairman Arlen Specter (R-Pa.) disclosed his plans to seek her views on some Bush administration policies, including the detention of suspected terrorists at the military prison at Guantanamo Bay, Cuba.

With support for Miers among many Republican senators apparently crumbling, Majority Leader Bill Frist (R-Tenn.) spoke with Bush at the White House on Wednesday, although sources differed on the degree to which he signaled the difficulty that Miers faced in winning confirmation.

"I had spoken with the president [Wednesday], and spoke with the White House over the course of the day, and just really reflected where I thought things were and that we were on course to start the hearings, and that the hearings would ultimately determine the outcome," Frist told reporters.

But a Senate source close to Frist said that the senator was much blunter and more negative, and that he suggested Miers withdraw because her chances of being confirmed were not good. In phone calls to White House Chief of Staff Andrew H. Card Jr. and Deputy Chief of Staff Karl Rove, Frist "gave it to them straight," said the source, who spoke on background because of the private nature of White House conversations.

At least one call took place before -- and at least one shortly after -- Frist met with senior GOP senators for a 6:30 p.m. dinner in the Capitol, the source said.

Former senator Dan Coats (R-Ind.), who accompanied Miers to numerous private meetings with senators, told reporters yesterday that for "several days" Miers had been recognizing that she could not provide the documents that senators were demanding while also protecting the president.

"The central problem," Coats said, was that Miers did not have a deep paper trail or a history of judicial decisions, and "senators rightly wanted to see some objective evidence of what her judicial philosophy was. But as special counsel, she was in a position where she wanted and needed to protect the executive privilege of the president. . . . She was troubled by this conundrum."

While conservative groups and Republicans battled over Miers's nomination, liberal activists and Democrats were mostly silent. But with her withdrawing under pressure, Sen. Charles E. Schumer (D-N.Y.) said it will be easier for senators from both parties to press future nominees on their judicial and political views.

"I started out three years ago saying people should address their judicial philosophy," he said in an interview, "and now we have most people agreeing -- conservatives, liberals, moderates. I think it's going to be very hard for future nominees to avoid talking about their judicial philosophy."

Ralph G. Neas, president of People for the American Way, a liberal advocacy group, said the Miers battle shows that conservatives will not be satisfied unless they get a nominee who is "guaranteed" to vote what they consider to be the right way on their issues.

"I've never seen anything like the last few weeks," he said. "You've got a sitting president, and you have a wing of his own party just pummeling him day after day."

Roger Clegg, vice president of the Center for Equal Opportunity, which opposes many affirmative-action programs, said Bush erred in limiting his search to women and minorities when he chose Miers.

"I hope that this time around they will not exclude people just because they are white males, and that the decision is based on who is the best qualified," he said.

Staff writer Jo Becker contributed to this report.

Counsel Harriet Miers enters the White House on the day she handed President Bush a letter saying she was withdrawing her nomination to the Supreme Court, which Bush said he "reluctantly" accepted.On Oct. 17, Harriet Miers was surrounded by members of the media after meeting with Sen. Arlen Specter (R-Pa.). This week, Specter had said he planned to ask Miers about some administration policies.