Merrick Garland has been in this position before.
The last time a seat opened up on the U.S. Supreme Court, in 2010, he was widely considered a top candidate for the job and interviewed with President Barack Obama. But the slot ultimately went to Justice Elena Kagan.
It's not hard to see why Obama might again find the 63-year-old Garland an attractive nominee to replace Justice Antonin Scalia, who died last month. He has a reputation as a moderate, which could please Republicans, and a resume that makes him look like a lot of the high court's current members.
He graduated from Harvard College and Harvard Law School, a school attended by five other current justices and Scalia. He's now chief judge of the U.S. Court of Appeals for the District of Columbia Circuit, sometimes called the ``second highest court in the land'' in part because of the frequency with which its judges ascend to the Supreme Court just a few blocks away.
As a young lawyer, Garland clerked for two appointees of Republican President Dwight D. Eisenhower, the liberal U.S. Supreme Court Justice William Brennan Jr. and Judge Henry J. Friendly, for whom Chief Justice John Roberts also clerked. Before becoming a judge himself, he was a prosecutor and supervised Justice Department investigations into the 1995 Oklahoma City bombing and Unabomber Ted Kaczynski.
His background made him popular even with Republicans when he was nominated to the D.C. Circuit by President Bill Clinton in 1995, but the full Senate didn't initially act on his nomination. The issue wasn't Garland, Iowa Republican Sen. Charles Grassley said at the time, but whether the court needed another judge at all. Grassley is now the chairman of the Judiciary Committee, which would oversee any hearings on a nominee.
Garland was ultimately confirmed to the D.C. Circuit on a vote of 76-23 in 1997. Thirty-two Republicans voted in favor of his nomination, including seven who are still members of the Senate.
Despite his background, there are two possible stumbling blocks to his nomination: his age and the fact he is a white male. Most of the court's current members were nominated and confirmed while in their 50s. Justice Ruth Bader Ginsburg was the oldest at confirmation, at 60.
Presidents generally like to choose nominees younger than the 63-year-old Garland to ensure they will serve for a long time. Still, Justice Lewis Powell was 64 when nominated to the court in 1971, so Garland's nomination wouldn't be unprecedented. President Obama has also sought to diversify the court with his previous picks, choosing Justice Sonia Sotomayor, the court's first Hispanic justice, and Kagan, whose confirmation meant that for the first time there were three women on the court.
Garland's religion — he is Jewish — also wouldn't add to the diversity of the court. Three of its current members are Jewish and five are Catholic.