WASHINGTON, Jan. 13 - Judge Samuel A. Alito Jr. completed his testimony at his Supreme Court confirmation hearings on Thursday to a blast of opposition from Democrats, who signaled they would not support him. They also indicated, however, that they saw little chance of blocking his confirmation, even with a filibuster.
Several Democratic senators on the Judiciary Committee took the step of announcing, as Judge Alito sat before them, that they had been alienated by his 18 hours of testimony, which left them with doubts about his credibility, as well as deep concern about his record on abortion rights and his views on the White House's effort to expand the definition of executive power.
It seemed clear that Judge Alito, in contrast to John G. Roberts Jr., will draw few if any Democratic votes in the committee, and when his nomination goes to the full Senate.
"As your testimony in these hearings come to a close, I just have to tell you that I remain very troubled, not by anything in your personal history, so much as by your judicial views," said Senator Charles E. Schumer, Democrat of New York. "Unfortunately, by refusing to confront our questions directly and by giving us responses that really don't illuminate how you really think, as opposed to real answers, many of us have no choice but to conclude that you still embrace those views completely or in large part."
Today, the confirmation hearings continued with testimony from a six-member panel made up of law professors and former members of the government, each of whom was to speak for several minutes.
The first witness was a former clerk for Judge Alito, Nora Demleitner, a law professor at Hofstra University, who called Judge Alito "one of the greatest legal minds" of his generation.
A self-described "left-leaning Democrat," Ms. Demleitner said the judge has many supporters who are liberal, and that she believed his confirmation would not "pose a threat" to women or immigrants.
On Thursday, Republicans, satisfied by the course of the hearings, disputed the Democratic characterization of Judge Alito, arguing that he had systematically answered questions posed to him dealing with the concerns of his opponents.
"I have to say, I deplored, really deplored, some of the tactics that have been used in this hearing," said Senator Orrin G. Hatch, Republican of Utah.
Judge Alito, Mr. Hatch said, "has answered more questions in more definitive ways than any Supreme Court nominee in my 29 years here in the United States Senate."
Senate aides said they expected the panel, which is made up of 10 Republicans and 8 Democrats, to split along party lines when it votes in the next 10 days. Judge Roberts drew three Democratic votes.
Democrats have blocked some of President Bush's nominations to federal court positions using a filibuster or just the threat of extended debate, but some Democrats and Republicans said they would agree to a filibuster only in extraordinary circumstances. Democrats said it was unlikely they could assemble the support needed for a filibuster, but said they would decide next week.
Robert Stevenson, a spokesman for Senator Bill Frist of Tennessee, the majority leader, said nothing had emerged from the hearings that would remotely justify the Democrats' seeking a filibuster.
The chances of a Democratic filibuster faded after the third day of hearings, as a spokeswoman for Senator Olympia J. Snowe of Maine, a moderate Republican, announced that Ms. Snowe would oppose it. Her decision is pivotal because she was one of seven Republicans who had joined an earlier successful effort to block Republican leaders from changing Senate rules to prevent filibusters against judicial nominations.
President Bush called Judge Alito from Air Force One after the hearing to congratulate him, Scott McClellan, the White House spokesman, said. The president told Mr. Alito he "showed great class" during the questioning, Mr. McClellan said.
Committee Democrats pressed Judge Alito on his views on executive power, his failure to recuse himself in a case involving the Vanguard mutual fund firm that handles his investments, and his membership in a Princeton group that opposed affirmative action at the university.
In an unusual move that drew criticism from Democratic senators and some former judges, several federal judges from Judge Alito's court - some sitting and some retired - appeared before the committee.
Judge Edward R. Becker, the former chief judge of the United States Court of Appeals for the Third Circuit, in Philadelphia, said he and his fellow judges believed that Judge Alito would be a superb justice.
"He is brilliant. He is highly analytical and meticulous and careful in his comments and his written work," Judge Becker said.
Judge Becker said that although testimony from a judge's colleagues was unusual, he thought it valuable because they knew him best.
But the practice of sitting judges endorsing a nomination drew criticism. Several Democrats said Judge Alito could well find himself, on the Supreme Court, passing judgments on the lower court rulings of many of the judges who told the Senate it should confirm him.
Judge Patricia M. Wald, a former appeals court judge, told reporters she thought such testimony was unwise because it would oblige future nominees to canvass their colleagues for support.
After Judge Alito got up from the witness chair, a panel of officials from the American Bar Association, which evaluates judicial candidates on their integrity, professional competence and judicial temperament, testified about its decision to rate Judge Alito as highly qualified to be a Supreme Court justice.
Marna Tucker, a Washington lawyer and a member of the A.B.A. panel, said that the lawyers and people they interviewed in reviewing Judge Alito's nomination had been startled to learn of his ties with the Princeton alumni club that had resisted efforts to enroll women and members of minorities at the university. Ms. Tucker said Judge Alito had told the A.B.A. panel, as he had told the senators, that he had no memory of being active in the organization, even though he listed his membership in it in a 1985 application for a job in the Reagan administration.
"We specifically asked him if this was to - since it was a job application, that was he pandering?" she said. "And he said it would be improper to not tell the truth on an application."
But, she said, "all of the people we spoke to on the courts - women and minorities, people who he had worked with, people who had sat on panels with him side by side in issuing judicial opinions - almost universally said that they saw no bigotry, no prejudice. They thought he was a fair man."
Senator Arlen Specter, Republican of Pennsylvania and chairman of the committee, said at the start of Thursday's hearing that Republican and Democratic lawyers had spent the night examining documents from William A. Rusher, an early leader of the Princeton group, at the Library of Congress, and had found no mention of Judge Alito. "Judge Alito's name never appeared in any document," Mr. Specter said.