In a dramatic flourish, Obama interrupted spokesman Robert Gibbs' daily press briefing to announce that he had just talked to Souter. The news of Souter's planned retirement had broken by then, but the White House had said nothing until the president came in.
Obama thanked Souter for his dedicated service, and quickly looked ahead to the nomination of a replacement.
"As I make this decision," Obama said, "I intend to consult with members of both parties, across the political spectrum. And it is my hope that we can swear in our new Supreme Court justice in time for him or her to be seated by the first Monday in October."
Souter informed Obama of his plans in a brief letter Friday. Obama praised Souter, who is leaving after nearly two decades in Washington. His retirement gives Obama his first pick for the Supreme Court.
Souter's departure is unlikely to change the court's conservative-liberal split. Obama's first pick is likely to be a liberal-leaning nominee, much like Souter.
The vacancy could lead to another woman on the bench to join Justice Ruth Bader Ginsburg, currently the court's only female justice.
At 69, Souter is much younger than either Ginsburg, 76, or Justice John Paul Stevens, 89, the other two liberal justices whose names have been mentioned as possible retirees. Yet those justices have given no indication they intend to retire soon and Ginsburg said she plans to serve into her 80s, despite her recent surgery for pancreatic cancer.
In Philadelphia, Sen. Arlen Specter said he would like to see more ethnic and gender diversity on the high court. "I think that, given the proportion of women in our society, that one out of nine is underrepresented," said Specter, a recent convert to the Democratic Party. "The court could use some diversity along a number of lines," he added, mentioning African-Americans and Hispanics.
Interest groups immediately began gearing up.
"Obama's own record and rhetoric make clear that he will seek left-wing judicial activists who will indulge their passions, not justices who will make their rulings with dispassion," said Ed Whelan, president of the conservative Ethics and Public Policy Center.
Nan Aron, president of the liberal Alliance for Justice, said, "We're looking for President Obama to choose an eminently qualified candidate who is committed to the core constitutional values, who is committed to justice for all and not just a few,"
Some of the names that have been circulating include recently confirmed Solicitor General Elena Kagan; U.S. Appeals Court Judges Sonya Sotomayor, Kim McLane Wardlaw, Sandra Lea Lynch and Diane Pamela Wood; and Leah Ward Sears, chief justice of the Georgia Supreme Court. Men who have been mentioned as potential nominees include Massachusetts Gov. Deval Patrick, Harvard Law professor Cass Sunstein and U.S. District Judge Ruben Castillo of Chicago.
Patrick said Friday he's "120 percent" focused on being governor, but did not rule out interest in a high court appointment.
The Obama White House began from almost its first days in office preparing for the possibility of a retirement by thinking about and vetting potential high court nominees. Those efforts only accelerated with Ginsburg's cancer surgery.
The timing may have been unexpected, but Souter has long yearned for a life outside Washington.
He has never made any secret of his dislike for the capital, once telling acquaintances he had "the world's best job in the world's worst city." When the court finishes its work for the summer, he quickly departs for his beloved New Hampshire.
The Rev. John McCausland, an Episcopal minister and friend of Souter's since college, said he and Souter have talked about what the justice would do after leaving the court. "He expects to go on senior status at the First Circuit," McCausland said, referring to the federal appeals court in Boston, "but not to work very full-time, and he's looking forward to finally having a life and catching up."
Souter has been on the court since 1990, when President George H.W. Bush tapped him for the Supreme Court.
At the time, Bush aide John Sununu, the former conservative governor of New Hampshire, hailed the choice as a "home run." And early in his time in Washington, Souter was called a moderate conservative.
But he soon joined in a ruling reaffirming woman's right to an abortion, a decision from 1992 that remains still perhaps his most noted work on the court.
Souter became a reliable liberal vote on the court on the social issues that regularly divide the justices on ideological grounds. He was one of the four dissenters in the 2000 decision in Bush v. Gore that sealed the presidential election for George W. Bush.
Yet as Souter biographer Tinsley Yarbrough noted, "he doesn't take extreme positions." Indeed, in June, Souter sided with Exxon Mobil Corp. and broke with his liberal colleagues in slashing the punitive damages the company owed Alaskan victims of the Exxon Valdez oil spill.
Souter is the court's 105th justice, only its sixth bachelor. He works seven days a week through most of the court's October-to-July terms, a pace that he says leaves time for little else. He told an audience this year that he undergoes "an annual intellectual lobotomy" each fall.
Souter earned his bachelor's and law degrees from Harvard sandwiched around a stay at Oxford University as a Rhodes scholar.
He became New Hampshire's attorney general in 1976 and a state court judge two years later. By 1990, he was on the federal appeals court in Boston for only a few months when Bush picked him to replace Justice William Brennan on the Supreme Court.
National Public Radio first reported Souter's plans Thursday night.
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