Justice John Paul Stevens announced his retirement last week after serving 34 years on the Supreme Court. For President Obama, choosing a nominee to replace him could potentially determine the direction the court takes for the next several decades.
Obama told reporters he would look for a candidate with qualities similar to Stevens: "An independent mind, a record of excellence and integrity, a fierce dedication to the rule of law and a keen understanding of how the law affects the daily lives of the American people."
The president said he would seek a justice who "knows that in a democracy, powerful interests must not be allowed to drown out the voices of ordinary citizens."
Analysts say the president will probably try to avoid a confrontation with Republicans especially during a fast-approaching midterm election season.
The three reported front-runners include Judge Diane Wood of the Seventh Circuit Appeals Court in Chicago, Solicitor General Elena Kagan and Judge Merrick Garland of the U.S. Court of Appeals, D.C. Circuit.
Kagan is considered by some Democrats to be the most likely choice, especially given her support from conservatives who respect her opening doors to them as former dean of Harvard Law School.
Garland is considered by others to be one of the safest choices, easiest to confirm because of his moderate views, which they feel would generate bipartisan support.
Wood is considered a liberal counterweight to conservatives on the court and could ignite fire from the right because of her views supporting abortion rights and separation of church and state.
Of the fewer than 10 possible nominees floating around, six are women. They include former Georgia Supreme Court Justice Leah Ward Sears. Known as an expert in family law, Sears is the first African American woman to serve as a State Supreme Court chief justice. She could become the first Black woman to sit on the country's high court.
Confirmation of the president's nominee requires a simple majority of the Senate. There is a chance Republicans will filibuster, although some have downplayed the idea.
Republicans are expected to paint the eventual nominee as a liberal ideologue. Some foresee Republicans using the process to try to shape the fall elections by riling up Tea Partiers, whoever the nominee may be. They may not derail the nominee, but they will likely seek to showcase hot-button issues and make the case that this is why voters need to elect Republicans in November, critics say.
Some think Obama will nominate someone seen as moderate to avoid a long, drawn-out fight or possible filibuster.
Sen. Charles Schumer, D-N.Y., told The New York Times that the focus should be on finding a nominee that could influence Justice Anthony M. Kennedy, the potential swing vote on the divided nine-member court, in liberal direction.
"One of the most important qualities for the new justice is the ability to win over Justice Kennedy," Schumer said, adding, "somebody who's going to be one of the five and not one of the four."
The White House has said it plans to select a nominee by early next month in time to allow for summer confirmation hearings and to seat the new justice before the fall term.
Stevens' departure is seen as the end of an era. He is the longest-serving justice by more than a decade.
A Republican nominated in 1975 by President Gerald R. Ford, Stevens gradually became the leader of the court's liberal wing. His majority opinions limited the use of the death penalty and expanded the rights of prisoners held at Guantanamo Bay, Cuba. He often voted in favor of criminal defendants, prisoners and those claiming to have been subjected to unlawful discrimination.
He is also known for writing two major dissents in two of the court's hard-fought recent 5-to-4 decisions, one regarding corporations being allowed to spend freely in candidate elections, and the other on a ruling that the Second Amendment protects an individual's right to own guns.