It’s being widely reported that Justice Breyer has decided to retire at the end of the Court’s term (i.e., in late June or early July). I assume that the reports are accurate. If so, I would guess that Breyer will soon send President Biden a letter stating his intention to retire (probably on the later of X date or confirmation of his successor).
This would be the fifth straight time that a Democratic president has been given the advantage of an early announcement of an intention to retire. In the last four instances, the president and the Democratic-controlled Senate have not moved with particular expedition:
On March 19, 1993, Justice Byron White informed President Clinton of his intention to retire. Clinton took more than two months—until June 22—to select Ruth Bader Ginsburg to fill the seat. Ginsburg’s confirmation hearing began on July 20, and the Senate confirmed her nomination on August 3.
Justice Harry Blackmun announced his retirement on April 6, 1994. Some six weeks later—on May 17—Clinton selected Breyer to fill Blackmun’s seat. Breyer’s confirmation hearing began on July 12, and the Senate confirmed his nomination on July 29.
In mid-April 2009, Justice David Souter privately notified President Obama of his intention to retire. He sent Obama a retirement letter on May 1. Obama nominated Sonia Sotomayor on May 26. Her hearing began on July 13, and the Senate confirmed her nomination on August 6.
Justice John Paul Stevens announced his intention to retire on April 9, 2010. Obama picked Elena Kagan to replace him on May 10. Her hearing began on June 28, and the Senate confirmed her on August 5.
This time might well be different, in part because the White House counsel’s office has presumably been preparing for the possibility of a vacancy from the beginning of Biden’s presidency, in part because Senate Democrats are keenly aware that they are just one seat away from losing control of the Senate.
As should be clear from the above examples, a president need not wait for a vacancy to arise before making a nomination. The post-confirmation act of appointment, by contrast, cannot occur until after the incumbent has vacated the seat. So if the Senate were to confirm Biden’s nominee before the end of the term (the presumed earliest date of Breyer’s resignation), Biden would have to wait until after Breyer’s resignation takes effect to appoint the confirmed nominee to Breyer’s seat.