WASHINGTON (AP) – Supreme Court nominee Samuel Alito seemed headed Thursday toward Senate confirmation, defending his judicial record to skeptical Democrats and praising the justice he would replace — Sandra Day O’Connor.

“I would try to emulate her dedication and her integrity and her dedication to the case-by-case process of adjudication,” Alito told the Senate Judiciary Committee on his fourth and final day of confirmation hearings.

The federal judge answered senators’ questions for 18 hours, prompting Committee Chairman Arlen Specter, R-Pa., to say Alito “demonstrated remarkable patience and remarkable stamina.”

President Bush tapped Alito to replace O’Connor, who has provided a decisive vote on issues such as abortion, the death penalty and affirmative action. Democrats argue that Alito, in 15 years as an appellate judge, has built a conservative record that foretells a rightward direction if he is confirmed to the high court.

Republicans maintain a majority on the committee and control the Senate — 55-44 with one independent. GOP lawmakers have predicted that Alito will win the backing of the Senate later this month, and little has emerged in the hearings to undercut that assessment.

Democrats have not ruled out the possibility of a filibuster that could require supporters to post 60 votes in the 100-member chamber. Judiciary Committee Democrat Dianne Feinstein has indicated a filibuster is unlikely and at least one conservative Democrat — Nebraska Sen. Ben Nelson — is leaning toward backing Alito. Nelson said Thursday that he has seen nothing that would disqualify the nominee.

Democrats peppered Alito about right-to-die cases, presidential authority, affirmative action and ethics on Day 4 of the hearings _ and elicited no more personal observations on such issues than they had in previous sessions.

Alito brushed aside attempts by Sen. Charles Schumer, D-N.Y., to get his opinion of a proposal to deny citizenship to U.S.-born children of illegal immigrants.

“I need to apply the same standard that previous nominees have applied, and that’s no hints and no previews. I can’t opine on them here off the cuff,” Alito said.

The 55-year-old federal judge did offer words of respect for the woman he would succeed.

“She has been known for her meticulous devotion to the facts of the particular cases that come before her and her belief that each case needs to be decided on its complex facts,” Alito said.

Earlier, he told the panel that Americans have a right to designate family members or friends to carry out their right-to-die wishes, an issue pushed to the forefront last year by the case of a brain-damaged Florida woman.

Sen. Patrick Leahy of Vermont, the ranking Democrat on the Judiciary Committee, cited the case of Terri Schiavo, the Florida woman who was at the center of a fierce fight between her husband and family over her fate that involved the courts, Congress and even the president.

Leahy asked: If a person has a living will, could he designate someone to decide whether to use extraordinary measures to keep him alive?

“Yes, that’s, I think, an extension of the traditional right that I was talking about that existed under common law, and it’s been developed by state legislatures, and in some instances, state courts to deal with the living will situation and advances … in medical technology, which create new issues in this area,” Alito said.

Schiavo suffered a brain injury in 1990 that left her in what some doctors called a “persistent vegetative state.” Her parents sought to keep her feeding tube in place while her husband wanted to have it removed, citing her wishes and setting off a bitter court battle.

Congress, Florida Gov. Jeb Bush and his brother, the president, all sought to have the feeding tube reinserted. Schiavo died on March 31.

Specter, the committee’s chairman, opened Thursday’s session by announcing that an examination of hundreds of documents from the founder of a controversial college alumni group found no mention of Alito.

The federal judge’s membership in Concerned Alumni of Princeton, which discouraged the admission of women and minorities at the Ivy League school, has been a divisive issue at Alito’s confirmation hearings.

In days of testimony, Alito has said he has no recollection of his membership in the Princeton group despite highlighting his involvement on a Reagan-era job application.

Specter said the panel’s staff combed through four boxes of documents at the Library of Congress of William Rusher, a founder of CAP, and came across nothing that mentioned Alito.

“The files contain dozens of articles, including investigative exposes written at the height of the organization’s prominence, but Sam Alito’s name is nowhere to be found in any of them,” Specter said.

Sen. Edward Kennedy, D-Mass., assailed Alito’s judicial record and testimony, citing the judge’s inability to recall his membership in the Concerned Alumni of Princeton and his explanation about his involvement in a case that Kennedy suggested raised questions about conflict of interest.

“The average guy has a hard time in getting a fair shake in Judge Alito’s courtroom,” Kennedy said, in his summary of Alito’s rulings.

The Democrat pressed Alito on why he didn’t disqualify himself from participating in a Vanguard case in 2002 despite his 1990 promise to the Senate to recuse himself in cases involving the mutual fund company.

Alito said it was an oversight and defended his statements to the committee.

“I have not given conflicting answers. I’ve been asked a number of different questions,” he said.

Bristling at the Democratic focus on what he called “phony issues,” Republican Sen. Orrin Hatch of Utah said, “I don’t think you’ve been fairly treated and it makes everybody wonder why would anyone want to do these jobs.”

On Wednesday, during a contentious Day 3 of hearings that at one point left Alito’s wife in tears, the federal appeals court judge remained unflappable under persistent questioning by Democrats who attacked his credibility.

“Many people will leave this hearing with a question as to whether or not you could be the deciding vote that would eliminate the legality of abortion,” Sen. Dick Durbin of Illinois said during Democrats’ grilling the nominee about whether he now believes, as he did in 1985, that the Constitution contains no right to an abortion.

Alito refused to say.

“I don’t think it’s appropriate for me to speak about issues that could realistically come up” before the courts, he said, falling back on a line also used by now-Chief Justice John Roberts and other Supreme Court members during their confirmation hearings.