John Roberts Jr became the US Supreme Court's youngest chief justice in two centuries by winning support from more than three-fourths of the Senate, even including half the 44 Democrats.
Roberts, at 50, becomes the 17th chief justice of the US to preside over a Supreme Court that seems as divided as the nation over abortion and other tumultuous social issues. The court's new term opens on Monday.
"The Senate has confirmed a man with an astute mind and kind heart," President George W. Bush said just before Roberts was sworn in by acting Chief Justice John Paul Stevens.
Roberts "will be prudent in exercising judicial power, firm in defending judicial independence and above all a faithful guardian of the Constitution," he said.
Bush is expected to make his second Supreme Court nomination within days, one that conservatives hope will move the court to the right. Replacing the late chief justice William Rehnquist with Roberts keeps the court's current balance, since both are conservatives like Bush, but replacing the moderate Justice Sandra Day O'Connor with a conservative could tilt it rightward.
Roberts called the Senate's 78-22 bipartisan vote for him "confirmation of what is for me a bedrock principle, that judging is different from politics."
All the Senate's 55 Republicans, independent James Jeffords of Vermont and 22 Democrats supported him.
He said he would try to "pass on to my children's generation a charter of self-government as strong and as vibrant as the one that chief justice Rehnquist passed on to us."
Rehnquist, for whom Roberts was a clerk in the early 1980s, died Sept. 3 at age 80. Roberts replaces him five years older than the youngest chief justice, John Marshall, who took over at age 45 when he was confirmed in 1801.
Roberts is the first new Supreme Court justice since 1994, and his age means he probably will influence US law for decades because of federal judges' lifetime tenure.
A crowd including seven of the eight sitting justices, Roberts' parents, Rosemary and John, children John and Josephine, Senate supporters and White House well-wishers stood and applauded as Roberts kissed his wife and shook Stevens' hand.
The audience also included Attorney General Alberto Gonzales and White House counsel Harriet Miers, both mentioned as candidates for O'Connor's seat.
Roberts took a separate judicial oath during a private White House ceremony attended by the other justices. A formal Supreme court ceremony was scheduled for Monday, before the opening of the term.
O'Connor, a moderate voice on the Supreme Court and one of only two women, is leaving after 24 years. Bush is the first president since Richard Nixon 34 years ago who has had simultaneous openings to fill on the high court.
The president originally named Roberts to succeed O'Connor in July. Rehnquist's death led to the switch to Roberts for chief justice on Sept. 6.
O'Connor remains on the court until the president selects a replacement and that person is confirmed by the Senate.
The only justice not at the White House was Antonin Scalia, who had a previous engagement.
Before becoming a federal appeals court judge, Roberts ranked among the nation's best appellate lawyers, arguing 39 cases, many in front of the same eight justices he now will lead as chief.
He won 25 of the cases.
Under Roberts, the court will tackle such issues as assisted suicide, campaign finance law and abortion this year, with questions about religion, same-sex marriage, the government's war on terror and human cloning looming in the future.



