The retirement of Justice Sandra Day O'Connor has opened the way for an array of candidates to the US Supreme Court.
Judge John Roberts, who was originally nominated to replace Justice O'Connor, has now been confirmed as Chief Justice - replacing the late William Rehnquist.
Ms O'Connor was the first woman on the court and a key "swing voter".
The BBC News website examines some of the likely candidates to succeed her.
Judge Samuel Alito, 55, of the Third Circuit in Philadelphia, is considered a quiet and retiring member of the federal appeals courts.
The judge, of Italian background, was appointed to the bench in 1990 by the first President George Bush.
In 1991, he voted to uphold all restrictions to abortion in Pennsylvania law, including a requirement that a woman inform her husband that she is seeking an abortion. This was struck down by the Supreme Court in a decision that reaffirmed the landmark Roe v Wade case.
Judge Alito worked in the Reagan administration's Justice Department and became US attorney for New Jersey in 1987, a post he held for three years. He is seen as a staunch conservative.
EDITH BROWN CLEMENT
Edith Brown Clement, 57, is currently a judge on the 5th US Circuit Court of Appeals - to which she was nominated by President Bush in 2001.
Clement is not seen as a hugely divisive figure. Analysts say she has yet to attract much attention for her writings off the bench and many of her decisions have been in relatively routine and uncontroversial cases.
She was educated at the University of Alabama and qualified in law at the Tulane Law School in 1972. She was a District Court judge in Eastern Louisiana, until she moved to the circuit court.
In her 16 years as a private sector lawyer, she specialised in civil litigation involving maritime law, representing oil companies, insurance companies and the marine services industry in cases before federal courts.
She is also a member of the Federalist Society, an influential conservative legal organisation.
John Cornyn, 53, is a Republican senator for Texas and a friend of President George W Bush.
Before winning his Senate seat in 2002 he served on the Texas Supreme Court
and as Texas attorney general.
He is the only senator with appellate court experience and serves on the Senate Judiciary Committee.
Justice Maura Corrigan, 56, was elected to the Michigan Supreme Court in 1998, where she served two terms as chief justice from 2001-2004.
Before that, she was chief judge at the Michigan court of appeals for six years.
The widow of a distinguished professor of law and the mother of a law student, Justice Corrigan is known for her strong views and involvement in community affairs. Among others, she is a member of the Pew Commission investigating foster care issues in the US.
Her involvement has won her a number of awards. The US department of health and human services honoured her for significant improvements to Michigan's Child Support Enforcement Programme in 2002, and the department of justice acknowledged her outstanding performance as assistant US attorney in 1985.
Justice Corrigan has written and published several treatises in legal publications, as well as teaching law at several institutions.
When her name was mentioned as a possible successor to Sandra Day O' Connor, she said she was "flattered and honoured", but added: "I'm not holding my breath."
Emilio Garza, 58, is a former Marine captain who was originally considered for a Supreme Court seat in 1991 by the first President Bush.
Appointed a federal judge by President Reagan in 1988, he was elevated to the New Orleans-based 5th US Circuit Court of Appeals in 1991.
Born in San Antonio, Texas, Mr Garza is said to be a popular candidate among many of his fellow Hispanics.
But his candidacy will not be welcomed by liberals who fear he is likely to support a change in laws protecting abortion rights.
He has in the past suggested he would vote to overturn the landmark 1973 Roe v Wade ruling that legalised abortion.
And he has also suggested that abortion regulation should be decided by state legislatures.
"Ontological issues such as abortion are more properly decided in the political and legislative arenas," he wrote in a 1997 opinion.
Alberto Gonzales, 49, became US attorney general in February. He was previously President Bush's chief lawyer at the White House.
He is a long-time Bush ally who played an important role in shaping legal opinions about the treatment of prisoners captured in Afghanistan and Iraq.
He was criticised by some human rights groups after writing a memo to the president in which he said the war against terrorism was a "new kind of war" that rendered obsolete Geneva's strict limitations on questioning of enemy prisoners. He has also made it clear that he does not approve of torture.
He first became a legal adviser to Mr Bush in 1995, when the president was governor of Texas.
In 1997, Mr Gonzales became Texas secretary of state, working closely with Mr Bush on legal issues and later became a judge of the Supreme Court in Texas.
He is a former law professor at the University of Houston.
EDITH HOLLAN JONES
Edith Hollan Jones, 55, was nominated to the 5th US Circuit Court of Appeals by President Reagan, and has served on the bench since 1985.
The first President Bush considered her for a vacancy on the Supreme Court in 1990 but nominated David H Souter.
She is seen as an outspoken conservative who has been a proponent of speeding up death penalty executions and has previously called into question the reasoning behind the Roe v Wade abortion ruling.
In a 2004 opinion she wrote: "If the courts were to delve into the facts underlying Roe's balancing scheme with present-day knowledge, they might conclude that the woman's choice is far more risky and less beneficial, and the child's sentence far more advanced, that the Roe court knew."
Edith Jones was born in Philadelphia and attended Cornell University. She qualified in law at the University of Texas Law School in 1974. In private practice she specialised in bankruptcy law.
J MICHAEL LUTTIG
J Michael Luttig, 51, currently on the Fourth Circuit Appeals Court, is considered a rising star in conservative circles. He is seen as an independent thinker with a piercing intelligence and a blunt manner.
Since becoming a judge in 1991, he has not been afraid of making controversial rulings. In 1999, for example, he struck down legislation on domestic violence on the grounds that Congress had overstepped its authority.
Mr Luttig is also seen as fiercely independent, and has criticised other judges in the past for being swayed on ideological grounds rather than judicial argument.
Mr Luttig's father was shot dead in 1994 in a carjacking by juvenile offender Napoleon Beazley. Beazley was later executed in a controversial case which went right up to and split the Supreme Court.
Michael McConnell, 50, is a former University of Chicago law professor who was nominated to the 10th Circuit Court of Appeals in Denver by President Bush in 2001.
More than 300 law professors signed a letter in 2002 endorsing his appellate court confirmation. There were liberals as well as conservatives among them - but there was also strong opposition from groups including the left-leaning People for the American Way Foundation, which called him "dangerous to women's rights".
Described by his supporters as an intellectual powerhouse, Mr McConnell opposes the strict separation of church and state, arguing that religious schools should be allowed to receive direct subsidies. He has also called for a constitutional amendment to ban all abortions, which he has called "evil" - including in cases of rape and incest.
Mr McConnell is also championed by the conservative right for his support for federalism, arguing against the role of central government in protecting civil liberties and working conditions.
Officially described as deputy chief of staff for policy, Harriet Miers, 60, has been serving as President Bush's top legal counsel since November 2004.
But she has never served on the bench.
"Harriet Miers is a trusted adviser on whom I have long relied for advice," said Mr Bush when he elevated her from the position of assistant to the president and staff secretary to top adviser.
She and Mr Bush go back a long way - having met in Texas in the 1980s. She served on his gubernatorial campaign in 1994 - and again during his presidential election of 2000.
Friends and colleagues describe the single woman as assertive and ambitious, whilst being discreet and selfless.
"She is defined by hard work, dedication and client loyalty," says Jerry Clements, partner at the Locke Liddell & Sapp firm of lawyer in Texas where she worked before moving to Washington DC.
And her hard work appears to have paid off - not only in mounting the echelons of power but also in overcoming gender-based bias. "She just overcame any obstacles with hard work and dedication," said Mr Clements, becoming the first woman hired by Locke Purnell Boren Laney & Neely - an old Dallas legal firm.
In 1992, Harriet became the first woman president of the Texas State Bar, having become the first woman president of the Dallas Bar Association in 1985.
Priscilla Owen, 50, was confirmed in May for a seat on Court of Appeals 5th Circuit after a long Senate battle.
The Senate confirmed her by a 55-to-43 vote after a bipartisan group of senators put together a compromise that ended a Democratic filibuster of her nomination.
The Texas lawyer is a former justice on the state Supreme Court.
JANICE ROGERS BROWN
Janice Rogers Brown, 56, former California Supreme Court justice, is the second black woman to sit on the Court of Appeals for the District of Columbia.
Seen as an outspoken conservative, she was confirmed by the Senate in June after a bitter process in which Democrats blocked her nomination.
JAMES HARVIE WILKINSON III
Judge James Harvie Wilkinson of the US Court of Appeals in Richmond, Virginia, is the oldest of the likely contenders at 61.
Judge Wilkinson was nominated to the circuit bench by Ronald Reagan in 1984, and has established a conservative record.
Supporters believe his intellect, experience and gracious manner make him the ideal choice.
In a 1985 book, One Nation Indivisible: How Ethnic Separatism Threatens America, Judge Wilkinson criticised affirmative action and said it was a cause for racial division.
He has had a long affiliation with the Republican Party.