"Sam Alito is a brilliant and fair-minded judge who strictly interprets the Constitution and laws and does not legislate from the bench. He is a man of deep character and integrity, and he will make all Americans proud as a justice on our highest court," President Bush said in a statement after the confirmation vote.
Chief Justice John Roberts administered the judicial oath and constitutional oath, by which Alito pledged equal justice for the rich and the poor, and to uphold the Constitution. Roberts, new to the Supreme Court himself, administered the oaths to an associate justice for the first time.
Alito and his wife, Martha, had watched the Senate floor vote with President Bush in the White House. After Alito had earned enough votes to be confirmed, Bush and his staff, including former Supreme Court nominee Harriet Miers, congratulated the newest justice. Bush then left to host a luncheon of the top news anchors from the networks and cable TV channels for an off-the-record preview discussion of his Tuesday night State of the Union speech.
Accompanied by his wife, Alito headed over to the Supreme Court building for his investiture. He and Roberts, both Bush nominees, are expected to attend Tuesday night's address.
The Senate vote put to bed the most partisan Supreme Court nomination since Justice Clarence Thomas' confirmation in 1991. Four Democrats joined 54 Republicans in support of Alito. Thomas received a slimmer margin of victory, 52-48, but at the time received the votes of 11 Democrats who broke from party ranks.
"I'm concerned about his philosophy of the Constitution, his great effort of many years to expand presidential power at a time when there are real serious questions about the powers the president has," said Sen. Jack Reed, D-R.I., who voted against Alito's confirmation.
Reed added that he feared Alito's addition to the bench would mean more decisions restricting Congress' power to legislate.
Sen. Arlen Specter, a pro-choice Republican who chairs the Senate Judiciary Committee, said he based his affirmative vote on Alito's credentials, not speculation about the future.
"And we have seen, in the long history of the court, that there's no way to determine in advance how a nominee is going to vote," Specter said. "We have the three authors of the opinion in [Planned Parenthood of Southeastern Pennsylvania v. Casey] on a woman's right to choose, who had been very much against a woman's right to choose before they got to the court. When they looked at the precedents, when they looked at the tradition, when they looked at the reliance, they supported that principle."
Maine Sen. Olympia Snowe, a pro-choice Republican, was the final holdout in her party on Alito's nomination. But Tuesday morning she announced she would vote for Alito, joining fellow pro-choice Maine Republican Sen. Susan Collins. Pro-Alito interest groups had infused the state with ads and activists, anticipating a fight for the Mainers' votes. Collins announced her support for Alito only last week.
Alito replaces the court's first woman justice, Sandra Day O'Connor, a moderate conservative Reagan nominee and key swing vote on such high-profile issues as abortion, church-state separation and affirmative action. O'Connor has also in recent opinions demonstrated skepticism of President Bush's executive power claims in prosecuting the War on Terror. Democrats suspected that Alito will be friendlier to presidential power arguments.
The vast majority of Democrats, one Republican, Lincoln Chafee of Rhode Island, and the Senate's lone Independent, Jim Jeffords of Vermont, protested Alito's nomination primarily over issues such as abortion rights and executive power. A last-ditch effort to filibuster the nomination failed on Monday, when the Senate voted 72-25 to end debate and allow a simple majority vote.
"I think this vote is part of a long practice, ever since the confirmation battle over Justice Rehnquist to become chief justice, where Republican nominees have been treated in a despicable fashion," said Orrin Hatch, a Republican member of the Senate Judiciary Committee who voted in favor of Alito.
But Reed and other Democrats have been quick to point out that conservative Republicans sabotaged Miers, Bush's second choice to replace O'Connor.
"It's a funny degree of rancor," Reed said, acknowledging that the battle over Alito's nomination had taken some nasty turns. "Just a few weeks ago we were considering Harriet Miers as a Supreme Court nominee, but ... because of opposition in the Republican Party something very, very rancorous drove her out."
Sen. Trent Lott, R-Miss., blamed the hostilities on Democrats.
"Frankly, I think things have been spiraling down on the judicial nominations in the Senate ever since the Bork vote. It really Borked the whole process," the former Majority Leader told FOX News, referring to failed Supreme Court nominee Robert Bork.
Miers, who serves as White House counsel, withdrew her nomination less than a month after Bush gave her the nod. Roberts had been the president's first choice to replace O'Connor but was re-nominated to replace William H. Rehnquist after the late chief justice died last summer.
Alito, 55, has taken a career path very similar to Roberts'. Both were rising stars in former President Reagan's Justice Department who went on to serve as judges, in Alito's case the 3rd Circuit Court of Appeals for 15 years. Unlike Roberts, Alito was a federal prosecutor who has never worked in the private sector.
Alito and Roberts' presence at the State of the Union address will be a boost for the president. The two newest additions to the Supreme Court represent victories for Bush in a year that has been packed with scandals and unsteady popular support. Bush promised to shift the court rightward in his 2000 and 2004 election campaigns.
While the constitutional oath is generally administered at the White House, separately from the judicial oath, Roberts administered both oaths "so that Justice Alito could begin to participate in the work of the court immediately," according to a statement from the court.
The court also announced that Alito's formal investiture would occur at a later date. Roberts' investiture took place on his first day hearing oral arguments, also the court's opening day last fall. The court is on winter break until Feb. 17, and won't be hearing oral arguments until Feb. 21.
The White House invited senators to attend a reception in Alito's honor Wednesday afternoon. President Bush on Wednesday will be in Nashville, Tenn., where he is giving the traditional post-address policy speech, and is expected to fly back in time for the reception.
While Tuesday's vote proceeded as expected, there was one near-surprise: a distracted Democratic Sen. Max Baucus mistakenly voted yes when he meant no. He blamed Senate Minority Leader Harry Reid, who was chatting up the Montanan on a pending tax reconciliation bill. Baucus' alarmed colleagues alerted him to the error and he changed his vote back to a no.
'A National Icon'
O'Connor and several other justices attended Alito's closed-door swearing in. After Tuesday's events, her resignation, submitted last July, became official.
O'Connor's reputation as a fair-minded, pragmatic and compassionate jurist who is also a strong federalist has eclipsed her significance as the first woman on the nation's highest bench. O'Connor, who turns 76 in March, is retiring to care for her ailing husband.
"Justice O'Connor was the first woman ever to sit on the Supreme Court, and she is one of the most admired Americans of our time, or any time. Our nation is grateful to Justice O'Connor for her extraordinary and dedicated public service, and Laura and I wish her and John all the best," Bush said Tuesday.
Reid, speaking before the floor vote, attributed his vote against Alito to his respect for O'Connor, whom he called "a national icon who has been a voice of moderation and reason on the court for the last quarter of a century." Reid added that he was especially disappointed to see the court lose one of its two women, echoing sentiments from women's and civil liberties groups.
O'Connor's admirers were also troubled by the court's new makeup, less for its more lopsided gender ratio than for how it might impact decisions.
"She was the moral center of the court," observed Marci Hamilton, one of the justice's former clerks. "On contentious issues she was the swing vote, but she determined every case would be decided on the basis of that case — she was never interested in the abstract."
Hamilton also noted that the court was losing the experience and insight of its sole onetime legislator. O'Connor served in the Arizona state Senate from 1969 to 1975, and became the first female Republican majority leader in the country.
"It is a huge loss in the sense that when the government comes in and makes its arguments, it's easy to discount them when you don't understand how the system works," Hamilton, a professor at Yeshiva University's Benjamin N. Cardozo School of Law, told FOXNews.com. "She was always looking to the whole meaning of the statute and the pragmatic effect of the statute."
Even those who might have been disappointed by O'Connor's decisions on social wedge issues like abortion had the highest praise for her as a jurist.
"[Alito's confirmation] marks the end of the public service of a great American and public servant from my state of Arizona, Justice Sandra Day O'Connor, who served on the court for over a quarter of a century," said Republican John Kyl, who called Tuesday a "bittersweet" day.
"I do also want us to remember Sandra O'Connor for the service that she has provided to our country as an associate justice on the Supreme Court and, really, all of the public service during her career in Arizona as well. She will be missed," he said.
Those who watched Alito's confirmation hearing were quick to note the lack of crackle and pop in his personality, and Hamilton predicted O'Connor's departure would sap the court of some of its congeniality.
"She was the social glue that held them together. ... Even as she was being attacked by other justices, she never succumbed to language in an opinion that she would come to regret. Her responses were always professional, cool and evenhanded. It set the tone for everyone else," Hamilton said.
"Even if they all vehemently disagreed, that night they would go to dinner together. Neither Alito nor Roberts would fill that role."
FOX News' Trish Turner contributed to this report.
An earlier version of this story erroneously indicated Sandra Day O'Connor was in Arizona and not in Washington to attend Alito's investiture.