While President Bush yesterday led a public campaign to shore up support for Supreme Court nominee Harriet Miers, his top White House aides and Republican National Committee Chairman Ken Mehlman launched a behind-the-scenes barrage of phone calls and e-mail to influential conservatives urging them to overcome their skepticism.

The effort to rally the president's usual allies met with uncertain results, winning some support but leaving conservatives coolly uncommitted about whether Bush made a wise choice.

"She may turn out to be the greatest thing since Antonin Scalia, but when will we know that?" said Jan LaRue, chief counsel of Concerned Women for America, a conservative advocacy group that is so far unconvinced by the lobbying. LaRue said that her organization cannot endorse Miers until it learns more about her legal views.

Some liberal advocacy groups, meanwhile, voiced cautious optimism that she could prove to be a moderate on some issues most important to their members.

The hesitancy and evident puzzlement about Miers is noteworthy in a capital in which most political advocacy groups in recent years have been believers in the imperative of "rapid response."

With the high court closely divided on many social and civil rights issues, advocates spent years preparing for what they anticipated would be an all-out fight over its direction. Groups on both sides had raised millions of dollars, established war rooms and built extensive databases in preparation for the next explosive battle in the nation's culture wars. At stake are issues including the right to abortion, the role of religion in public life and affirmative action.

But Bush's selection of Miers, his White House counsel and former personal attorney, for the seat being vacated by Justice Sandra Day O'Connor, the high court's swing vote, has splintered conservatives and left liberals largely mute because there are few clear clues about where Miers stands on many divisive issues.

Miers, 60, has never been a judge, having spent the bulk of her career as a corporate lawyer and a prominent member of the Texas legal establishment. The little that has emerged about her record reveals no clear indication of her judicial philosophy or social views.

Miers has described herself as a born-again Christian and regular churchgoer. But as a candidate for the Dallas City Council in 1989, she endorsed the idea of gays having the same civil rights as others. At the same time, she opposed repeal of a Texas law outlawing sexual acts between consenting gay adults. She once made a small contribution to a fundraiser of an antiabortion organization.

As president of the Texas and Dallas bar associations, she built a reputation for reaching out to women and minorities to fill key posts. Miers "was emphatic about building stronger relationships with the African American and Hispanic bar," said Ron Kirk, a lawyer and former mayor of Dallas. But she is also a key member of the Bush administration, which opposes many race-conscious affirmative-action efforts.

Those conflicting signals are heartening to many liberal advocates, who feared that Bush would replace O'Connor with a nominee who was an unquestioned judicial conservative. "It's obvious from the firestorm we've seen that Miers wasn't on the short list of the ideological right," said Wade Henderson, executive director of the Leadership Conference on Civil Rights. "While that doesn't tell us who she is, that is a fact worth noting."

President Ralph G. Neas said the liberal People for the American Way is taking a wait-and-see approach toward Miers, saying he needs to learn much more before adopting a position. "The hearings are always the most critical part of a confirmation process," Neas said. "When you have someone like Harriet Miers, the hearings are all important."

Early White House lobbying of James Dobson, chairman of Focus on the Family and one of the most influential leaders of the religious right, resulted in his support of Miers. The nomination also picked up a significant endorsement yesterday from the National Right to Life Committee: Executive Director David N. O'Steen said Bush has an "excellent record" of appointing strict constructionists to the courts, and he expressed confidence Miers "will abide by the text and history of the Constitution."

But many other prominent social conservatives yesterday remained firm in their refusal to line up behind the nominee. Tony Perkins, president of the Family Research Council, maintained there is not enough information about Miers to determine whether she is in the mold of Scalia and Clarence Thomas, the two conservative justices Bush has cited as models for court nominees.

Phyllis Schlafly, founder of the Eagle Forum, said she is worried that Miers "is a female Souter," referring to Justice David H. Souter, who was appointed by Bush's father but turned out to be a moderate, severely disappointing conservatives. Schlafly was also critical of the conservative credentials of newly installed Chief Justice John G. Roberts Jr.

"Bush is building his own empire without regard for the conservative movement or the party," she said. "People expected him to move the Supreme Court away from its activism, and there is nothing in Miers and Roberts to show that he has moved the court one inch away from where it is."

Harriet Miers, White House counsel and now nominee to the Supreme Court, with President Bush in the Oval Office in July.