THE NOMINATION of Sandra Day O'Connor to the Supreme Court has much more to do with the Reagan administration's continuing commitment to smart politics that it has to do with any commitment to equal rights for women. As historic and symbolic as it might be to finally have a woman on the Supreme Court, the most immediate impact of the nomination is that it will diffuse for some time the criticism that the Reagan administration is insensitive to the interests of women.

For a president who has consistently fared worse with women in polls, who has been repeatedly criticized by women leaders throughout his party for his failure to appoint women, and who is backpedaling on affirmative action, this was a splashy move that cannot help but boost this popularity among women -- at least for a while. That he has gotten more mileage out of this one appointment than President Carter got out of more than 40 appointments of women to the federal bench is but one measure of the political brilliance of the nomination.

Another -- and the assumption has to be that it was by design -- is that the appointment has created a breach between the president and the coalition of antiabortionists and right-wing fundamentalists whose influence on the administration has been of growing concern to moderate Republican women. That breach, created by the coalition's shrill overractions to O'Connor's abortion record, will help dissipate the perception that the president is unduly beholden to a group of people who traditionally have been quarantined on the fringes of American politics.

Bobbie Green Killberg, a former associate legal counsel to President Ford and the vice chairman of the Reagan-Bush women's policy advisory board during the campaign, is a moderate who believes the nomination of a political moderate to the Supreme Court is a major statement of the administration's intentions.

"They're making a statement to the American people that Ronald Reagan is not going to be an ideologue in his nominations to the court, that he's going to look at the broad record of an individual when he appoints someone, that he's going to appoint a solid person in every sense of the word," she said. "That's key to the future of the Supreme Court. . . .

"To me," said Kilberg, "one of her additional assets is the nature of her opposition. It is inconceivable to me that they wouldn't know they'd get this reaction from the New Right. I think it's a move toward the political center . . . and a statement that goes way beyond the court. . . . I think Ronald Reagan is going to continue to surprise us during his presidency."

It is clear from the reaction of the New Right leaders that they wanted to subvert the mission of the Supreme Court of the United States to one narrow cause. They jumped on the fact that O'Connor, while in the Arizona state legislature, cast several votes that they considered "pro-abortion." That she also voted for a measure that would allow hospital employes the right to refuse to perform abortions did not matter. That she assured the president that she is personally opposed to abortion was not enough for them. For all their talk of God, motherhood and country, the New Right leaders have made it clear that in the land of their dreams no one is eligible for the Supreme Court who is not as fanatically opposed to abortion as they are.

How much they were willing to compromise the Supreme Court for the sake of a single issue is even more striking if you think how few abortion questions will be coming to the court. Out of 4,000 petitions for review of cases given the court each term, only a handful deal wth abortion Of the 300 or so cases the court agreed to review during the past two terms, it issued decisions in only two cases that involved abortion.

Far more important than the judge's position on abortion ought to be what kind of a judge she is and what she will bring to the court. At 51, she brings youth. She brings the experience of having excelled in situations in which she was in a minority. She brings the experience of having worked in and led a state legislature -- an experience that gives her a unique perspective on a court that examines state legislation but whose justices have no experience as state legislators. And, having served on a state court, she brings still more experience to a court that has not had an appointee with that background snce Justice William Brennan.

President Reagan had a lot to lose by appointing an ideologue and he had a lot to lose by appointing a woman who, regardless of her abortion views, could have been found judicially less than competent. From everything we know so far about Judge O'Connor, Reagan did well by himself and well by the American people.