Barack Obama is preparing to make his second appointment to the US Supreme Court, following Justice John Paul Stevens' announcement that he will retire this summer.
He is expected to nominate a successor aligned with the court's more liberal justices - Ruth Bader Ginsburg, Steven Breyer and his first appointee, Sonia Sotomayor.
He has met several possible candidates, including Solicitor General Elena Kagan, Justice Diane Wood and Justice Sidney Thomas, at the White House, and is expected to make a choice in the week beginning 16 May.
ELENA KAGAN, SOLICITOR GENERAL
Background: Elena Kagan is the US's first female solicitor general. The former Dean of Harvard Law School has spent much of her professional life in academia.
Early in her career she was a clerk for a US Court of Appeals Judge and later for former Supreme Court Justice Thurgood Marshall. Like Mr Obama, she worked on the prestigious Harvard Law Review as a student.
Pros: Ms Kagan has already been through one senate confirmation. Her varied experience outside the courtroom appeals to Mr Obama.
At 50, she would most likely serve on the court for decades, making her, potentially, an enduring part of Mr Obama's presidential legacy.
Having not previously been a judge, she has few rulings for critics to scrutinise. This may or may not be an advantage.
Cons: Some liberal Democrats worry that Ms Kagan's centrist tendencies - she's helped make the case for continuing Bush Administration policies on state secrets and the use of military commissions to try terror suspects - will shift the court rightward. Her staunch advocacy of gay rights, on the other hand, may concern Republicans.
Prior to becoming solicitor general, she had never argued a case in court. But now she's representing the government in some some key cases; this means that as a Supreme Court justice, she may have to excuse herself from some pivotal decisions.
DIANE WOOD, FEDERAL JUDGE
Background: Diane Wood spent much of her early life in Texas, going on to graduate top of her class from the University of Texas Law School in 1972. She was a clerk for former Supreme Court Justice Harry Blackmun.
After working as a legal advisor for the Department of State and in private practice, she became the third female law professor at the University of Chicago, where she continues to teach.
Pros: Her history of liberal rulings as a judge on the Seventh Circuit Court of Appeals would please the Democratic left. Like the outgoing Justice Stevens, she has a reputation for building consensus with ideological opponents.
Cons: She would face serious opposition from Senate Republicans. Conservatives consider her rulings on social issues, particularly abortion, well outside the mainstream.
MERRICK GARLAND, FEDERAL JUDGE
Background: A former Principal Deputy Attorney General, Mr Garland oversaw the prosecutions of the Unabomber and Oklahoma City bomber Timothy McVeigh.
He served in the Department of Justice under the Democratic administrations of Presidents Carter and Clinton, and the Republican administration of George H W Bush.
He graduated first in his class from Harvard, before earning his postgraduate law degree there, with honours.
Pros: He receives rave reviews from lawyers and fellow judges, and has a reputation for being careful and fair in his rulings on the Court of Appeals for the District of Columbia. His confirmation would be fairly smooth.
Cons: Like Justice Breyer, Garland is a white Jewish male, so he wouldn't add to the court's diversity.
SIDNEY THOMAS, FEDERAL JUDGE
Background: Mr Thomas spent many years in private practice in his home state of Montana, where he also taught at a community college. He serves on the Ninth Circuit Court of Appeals, the nation's largest appeals court.
Pros: A widely respected judge, he's not from an Ivy League background or from Chicago, making him a down-to-earth choice by an administration that struggles to avoid appearing elitist.
Thomas would be the only current Supreme Court justice hailing from the Rocky Mountain region and has few apparent ties to DC. He would help bolster the president's narrative of breaking up the "insider" culture of Washington.
Cons: In 2006, Thomas ruled in favour of releasing Ahilan Nadarajah, a Sri Lankan Tamil and suspected terrorist who'd been in immigration detention for four years. His ruling, which was heralded as a victory for the left-wing American Civil Liberties Union, may come back to haunt him during confirmation hearings.
LEAH WARD SEARS, PARTNER, SCHIFF HARDIN
Background: Leah Ward Sears retired as Chief Justice of the Georgia Supreme Court last year.
She was the first African American chief justice in the US and the first woman to serve on the Georgia Supreme Court.
Her judicial career began on the Atlanta Traffic Court in 1985. She holds degrees from the University of Virginia, Emory and Cornell.
Pros: Her civil rights credentials and her pro-gay rulings, could make her make her attractive to Mr Obama, as a contribution to his presidential legacy.
Cons: Liberal activists have voiced concerns about the ties between Ms Sears and Conservative Supreme Court Justice Clarence Thomas. They fear that, as a form of mentor, he may influence her during her early days on the court.
ANN CLAIRE WILLIAMS, FEDERAL JUDGE
Background: Ann Claire Williams began her career as an inner city public school teacher. She spent nine years as an Assistant US Attorney in Chicago, ultimately becoming chief of the Organized Drug Enforcement Task Force.
She served for 14 years as a federal trial judge in Chicago and was the first African American appointed to the Seventh Circuit.
Pros: White House spokesman Robert Gibbs says President Obama is looking for a justice who understands "how the law affects real people in the real world, not just in a classroom, not just at a school". Ms Williams' teaching background helps her fit that bill.
She was appointed to judicial posts by presidents Reagan and Clinton, giving her resume a bipartisan flavour.
Cons: Nonetheless, as a Chicago liberal, she'll be heavily scrutinised by conservatives. Republicans are already aggravated by the number of left-leaning Chicagoans that Mr Obama has installed in Washington.
JANET NAPOLITANO, HOMELAND SECURITY SECRETARY
Background: Janet Napolitano was Arizona's attorney general before she became its governor. She previously worked in private practice as well as serving as a US Attorney under President Clinton.
Pros: She's from a Republican state and has formed an excellent working relationship with the president. Her tenure at Homeland Security has been relatively uncontroversial.
A skilled legal talent, she's generally considered moderate and balanced.
Cons: Napolitano was part of the legal team for Anita Hill, whose allegations of sexual harassment almost derailed the confirmation hearings for Supreme Court Justice Clarence Thomas in 1991. Napolitano would serve alongside Thomas, if confirmed.
Taking Napolitano away from her Homeland Security post also means Obama would have to find a new secretary for this complicated and pivotal position. Confirming that individual would be no mean feat considering the current polarisation of the Senate.