President Bush didn't come out and say he made a mistake, but that was the clear message of his announcement yesterday that he was accepting Harriet Miers's decision to withdraw as a nominee for the Supreme Court. And for a stubborn president whose greatest weakness has been a reluctance to admit and correct mistakes, the Miers pullback is a signal event.

Bush's retreat tells us what is obvious on so many fronts: This is an embattled White House that must now conserve its ammunition. With indictments possibly looming for one or more top White House aides, Bush simply could not afford a diversionary fight over Miers. He needed to shore up his conservative base, but even more he needed to avoid a losing fight. In that sense perhaps the president has finally overcome his fondness for Pyrrhic victories -- battles that leave him and the country weaker even if he wins.

Bush covered his retreat on Miers by arguing that he was defending the confidentiality of her White House records, which senators had demanded to see. But that shouldn't fool anyone: Bush was facing a rebellion by GOP conservatives and the growing likelihood that Miers's nomination would be rejected. This time he chose to fold a losing hand rather than persist.

Bush did the right thing, but I worry that it was for the wrong reason. The problem with Miers wasn't that she was insufficiently conservative -- who knew, in the jumble of her record, what her real legal views were? -- but that she obviously lacked the qualifications to sit on the nation's highest court. The judicial questionnaire she submitted was so weak that the Senate Judiciary Committee asked her to redo it; her personal visits with senators created so much confusion that aides suggested they be curtailed; her published writings were so vacuous they undermined her solid record as a corporate lawyer in Texas.

Yet, even a few days ago, Bush had seemed determined to push ahead with Miers. He repeated over and over what he had said in nominating her on Oct. 3: that she was a woman of strong character and sound legal philosophy who would make a fine justice. Even as the buzz of conservative dissent became a roar, Bush kept repeating his mantra about how she would be confirmed and how the country would come to know and appreciate her as Bush did. It was the judicial version of "stay the course."

I wish Bush had pulled back on other controversial issues. The nation would be better served, for example, if John Bolton were not our ambassador at the United Nations now. America needs a strong, effective advocate to shape Security Council debate, as in the wrangling over a resolution on Syria. But Bolton was so badly damaged by his confirmation hearings that it's clearly hard for him to play that role.

The biggest danger for Bush now is that he will circle the wagons even more tightly at the White House -- compounding his problem of political isolation. The polls show that Bush has been popular when he has found ways to communicate with the country as a whole, rather than just to the right wing of his own party. He has more than three years left as president; if he spends his time trying to please William Kristol and other right-wing critics, he will squander his opportunity to be an effective president. A nation at war cannot afford to be governed from the fringe.

Bush's problems will get much worse before they get better. As the Plame leak investigation runs its course, he may lose the advice of the two sharpest strategists in the White House, Karl Rove and Lewis "Scooter" Libby. To fill this vacuum, Bush must find a new center of gravity. The basic choice is either to lurch even more toward his conservative base or to reach out to the political center. My guess is that in the implosion of the Miers nomination, Bush will move right to "consolidate the base" -- even though that risks isolating him even more from the mainstream.

Presidents make mistakes. Bush made a big one with Harriet Miers, a decent lawyer and loyal friend, but a bad nominee for the Supreme Court. It's good that Bush recognized his error before he did even more damage to Miers and his own political fortunes. To save his presidency, Bush needs to find a voice that can rise above the nasty politics that were so evident in the Miers fight and speak to the country. This White House needs to understand that Bush's approval rating hasn't plummeted to around 40 percent because the country fears he isn't conservative enough.

Harriet Miers and President Bush in the Oval Office on the day her nomination to the Supreme Court was announced.