Ghana National Council

WASHINGTON, Jan. 11 - The Constitution does not say what criteria the Senate should use in deciding whether to confirm a Supreme Court nominee.

But at least one clear test has emerged over the first three days of Judge Samuel A. Alito Jr.'s confirmation hearings. This nominee must, it seems, continually refer to and, if at all possible, endorse the views of the woman he aims to replace, Justice Sandra Day O'Connor.

Senators from both parties have frequently used Justice O'Connor's opinions as a basis for questioning Judge Alito. The heavy emphasis on her work is a testament to her disproportionate influence on the court in her 25 years of service, and a reminder of the important role Judge Alito will assume if he is confirmed.

As two senators noted in their opening statements, Justice O'Connor has cast the decisive vote in almost 150 cases, many of them of great moment.

Whenever the opportunity arose, Judge Alito and his supporters highlighted instances in which he had ruled as she had. He invoked her name on 9 occasions, and he had good things to say about her decisions 10 times. On Tuesday, Senator John Cornyn, Republican of Texas, ticked off areas in which the two judges had agreed.

"Justice O'Connor and Judge Sam Alito both set limits on Congress's commerce power," Mr. Cornyn said. "Sandra Day O'Connor and Sam Alito both struck down affirmative action policies that had strict numerical quotas. And both - this ought to be a shocker to some based on what we've heard here today - is that both Justice Sandra Day O'Connor and Judge Sam Alito have criticized Roe v. Wade."

Democratic senators, on the other hand, worked hard to show that Judge Alito and Justice O'Connor were at odds, particularly in an important abortion case.

In his opening statement, striking a theme that has run through the hearings, Senator Charles E. Schumer, Democrat of New York, asked rhetorically, "Are you in Justice O'Connor's mold or, as the president has vowed, are you in the mold of Justices Scalia and Thomas?"

President Bush has said he would try to appoint justices like Antonin Scalia and Clarence Thomas, the court's two most conservative members.

By Wednesday morning, Senator Tom Coburn, Republican of Oklahoma, had grown frustrated with all the O'Connor talk. "The fact that you have to fit the Sandra Day O'Connor mold is really a misapplication," he said. "There is no precedent that would say that."

Judge Alito said he would be his own person, but not before offering one more tribute. "No nominee can ever be a duplicate of someone who retires," he said, "and particularly when someone retires after such a distinguished career and such a historic career as Justice O'Connor. Nobody can be expected, as a nominee, to fit that mold."

Judge Alito gave no indication, beyond saying he respected precedent and would proceed with an open mind, about whether he would follow the joint opinion Justice O'Connor signed in Planned Parenthood v. Casey, a 1992 decision affirming the constitutional right to abortion found by Roe v. Wade in 1973. Casey was, however, a 6-to-3 decision, and Judge Alito will not be in a position to move the court away from its support of the core right to abortion.

But Justice O'Connor did provide the crucial fifth vote in the court's last major abortion ruling, in 2000, striking down Nebraska's ban on what were called "partial birth" abortions. The court will soon decide whether to hear a challenge to a similar federal law, and in that case Judge Alito could alter the course of the court's abortion jurisprudence.

Judge Alito participated in the Casey decision in 1991 as an appeals court judge, and he seemed a little defensive in explaining his dissenting vote to uphold a Pennsylvania law that required women to notify their husbands before having abortions. The Supreme Court took the opposite view the next year.

All he had been trying to do in his dissent, Judge Alito explained, was to understand what Judge O'Connor had meant in some earlier decisions.

"There were just a few hints in those opinions about what she meant," Judge Alito said. "Based on the information that I had from Justice O'Connor's opinions, it seemed to me that this was not what she had in mind. Now, that turned out not to be a correct prediction."

In another exchange, asked whether he agreed with Justice O'Connor's statement in a 2004 decision that "a state of war is not a blank check for the president when it comes to the rights of the nation's citizens," Judge Alito did not hesitate.

"Absolutely," he said. "That's a very important principle."

In defending his dissent in a 10-to-1 decision of his court in an employment discrimination case, Judge Alito also invoked Justice O'Connor.

"When the issue went to the Supreme Court" in another case, he said, "Justice O'Connor wrote the opinion for the Supreme Court, and she agreed with my analysis."

In 1996, Judge Alito voted in dissent to strike down a law regulating the possession of machine guns, citing United States v. Lopez, a 1995 Supreme Court case that struck down a law banning the possession of handguns near schools.

Senator Jon Kyl, Republican of Arizona, was quick to note the lineup in the Lopez case. "By the way," Mr. Kyl said, "it was one of those decisions that Justice O'Connor was in the majority, a 5-4 decision in which her position could be characterized as the swing vote."

On Wednesday, Judge Alito said he would follow Justice O'Connor's approach in religion cases.

"Justice O'Connor pointed out something that's very critical in this area," he said. "She said there is a big difference between government speech endorsing religion and private religious speech. And private religious speech can't be discriminated against. It has to be treated equally with secular speech."

From the moment he was nominated in October, Judge Alito has made clear his fondness and admiration for Justice O'Connor. That was based in part, he said in remarks accepting the nomination, on something she had done at his first argument before the Supreme Court in 1982, an occasion that filled him with "a sense of awe."

"I also remember," he said, "the relief that I felt when Justice O'Connor, sensing, I think, that I was a rookie, made sure that the first question that I was asked was a kind one. I was grateful to her on that happy occasion, and I am particularly honored to be nominated for her seat."