Why not nominate vice justices for the Supreme Court?

As if President Obama did not have enough on his plate! He will soon need to nominate a Supreme Court justice to replace David H. Souter, who intends to retire. While Obama is at it -- and to make things easier next time around -- perhaps he should consider nominating a second justice now, to fill whatever vacancy might arise after Souter's departure.

Souter's formal letter to Obama indicates that he will step down at the end of this term -- presumably late June. But nothing prevents the president from nominating now and the Senate from confirming next month, while Souter is still a sitting justice. This would hardly be unusual. In a letter sent to President George W. Bush in July 2005, Justice Sandra Day O'Connor wrote that her resignation would become "effective on the nomination and confirmation of my successor" -- an event that did not occur until the middle of the following term. Chief Justice Warren Burger and justices Thurgood Marshall and Harry Blackmun also continued to sit during the process of nominating and confirming their successors.

But if the president may nominate a justice before a formal vacancy occurs, why can't he do so before an informal announcement of a planned retirement? Why shouldn't the president feel free in the next few weeks to nominate two people to the court -- an heir and a spare, one to fill Souter's seat and one to fill the next vacancy when it arises?

Consider first the efficiency advantages. Sitting justices would be free to leave whenever they wanted, without fear that the court would be crippled until they were replaced. Likewise, an unexpected death would not leave the court short-staffed because a pre-approved replacement justice would be ready to step in -- much as vice presidents and lieutenant governors stand ready to fill executive branch positions that suddenly open up.

There was a time when Senate confirmations were quick. The Senate confirmed George Washington's first six nominees to the court in two days. As late as 1975, Justice John Paul Stevens was confirmed less than three weeks after his nomination. But those days are gone. Since Robert Bork's failed nomination in 1987, the Senate has typically taken months to confirm even uncontroversial court nominees. Most recently, seven months elapsed between O'Connor's conditional resignation letter and the filling of her seat by Samuel A. Alito Jr.