In the Center, Hers Was the Vote That Counted

She heartened conservatives again in 1986 and 1989, when she voted to uphold abortion regulations in Pennsylvania and Missouri.

But in 1992, when appointees of Reagan and President George H.W. Bush seemed to have a majority to overturn Roe , O'Connor hesitated.

She invoked an alternative constitutional balancing test that she had hinted at in early opinions: that the right to abortion could be limited only as long as the state did not impose an "undue burden" on it.

She voted to reaffirm Roe , striking down the Pennsylvania law's requirement that wives notify their husbands before an abortion.

In 2000, O'Connor was also in the majority when the court ruled, 5 to 4, that a Nebraska law banning late-term abortion violated O'Connor's "undue burden" test. Yet she issued a separate concurring opinion suggesting she would not rule out all efforts to legislate against a procedure that opponents call "partial-birth" abortion.

Justice Harry A. Blackmun, the author of Roe , concluded it was no surprise the Supreme Court's first woman had voted to affirm Roe .

"She is a believer in states' rights in the sense that she feels an issue of this general nature should be left to the state legislatures and not be federally constitutionalized," Blackmun said in an oral history of his years on the court that was published early last year. But, he added, "she is a woman and may fear somewhat any accusation of being a traitor to her sex. Some women's organizations would so conclude."

Whatever her private motivations, O'Connor's ambivalent embrace of Roe was consistent with the American public's. According to Gallup polls going back to 1992, a significant majority opposes "completely" overturning Roe ; according to a 2004 Washington Post-ABC News poll, only 17 percent of Americans think abortion should always be illegal, while only 21 percent think it should always be legal.

During the 1980s and '90s, O'Connor helped the court establish the rule that affirmative action should be subjected to the same "strict scrutiny" as discrimination against minorities. As O'Connor saw it, only "compelling" governmental goals could justify affirmative action, and even then programs would have to be "narrowly tailored."

Yet for all her reservations about affirmative action, O'Connor never ruled it out. In her 1995 opinion enshrining "strict scrutiny" of affirmative action, for example, she insisted that the "unhappy persistence of both the practice and the lingering effects of racial discrimination against minority groups in this country is an unfortunate reality, and government is not disqualified from acting in response to it."

In 2003, when white students challenged their denial of admission in favor of black students with lower test scores at the University of Michigan, O'Connor backed the university.

Diversity in higher education could, indeed, qualify as a compelling state interest, she wrote for a five-member majority consisting of her and the court's four most liberal members. As long as a school did not mechanically assign minorities' applications extra points, but gave all students individualized consideration, its approach would be constitutional under Powell's opinion in Bakke .

Her opinion took sympathetic note of the views of large corporations, university deans and retired military officers whose friend-of-the-court briefs called affirmative action necessary to educate a racially integrated elite -- and, by implication, to preserve the stability and legitimacy of the American meritocracy. Her only nod to critics of the programs was her expressed wish that they might no longer be necessary in 25 years.

Once again, O'Connor's position -- diversity, yes, quotas, no -- was roughly in line with public opinion.

In a Fox News poll published shortly after the affirmative-action decision, O'Connor ranked as the Supreme Court justice Americans "most admire or agree with."