Judge Sonia Sotomayor's answers to a questionnaire she filled out for the Senate Judiciary Committee provides some additional information about the process by which she became Barack Obama's Supreme Court nominee.
In particular, it is revealed that the appellate judge was contacted four days before Justice David Souter announced he was retiring from the bench, meaning the White House either had its eyes on Sotomayor before it knew of a vacancy, or they were well-informed of Souter's impending retirement before it was publicly announced. Both may be true.
Additionally, Sotomayor seems to have conversed with nearly all the key players in the White House's Supreme Court vetting process before actually talking with the president himself. Her interview with Obama came nearly a month after the initial contact was made by chief counsel Greg Craig, and just under a week before she was announced as the choice.
Here is the relevant answer from Sotomayor's questionnaire.
I was contacted by Gregory Craig, White House Counsel, on Monday April 27, 2009, with respect to the possibility of a future Supreme Court vacancy. Between that date and the present, I have had frequent conversations with Cassandra Butts, Deputy White House Counsel, including near daily phone calls after Justice Souter on May 1, 2009 announced his intention to resign at the end of the current Supreme Court term. On May 14, 2009, I was interviewed in person at my office by Leslie Keirnan, an attorney at Zukerman Spaeder LLP. I was interviewed by telephone on Saturday, May 16, by Gregory Craig, Cynthia Hogan, Counsel to the Vice president, Ron Klain, Chief of Staff to the Vice President, David Axelrod, Senior Advisor to the President, Daniel Pfeiffer, White House Deputy Communications Director and Cassandra Butts. I was interviewed on Thursday, May 21, 2009 by members of the Administration including Gregory Craig, Cassandra Butts, Associate Counsel to the President Susan Davies, Chief of Staff Rahm Emanuel, David Axelrod, Ronald Klain, and Cynthia Hogan. Finally, I was interviewed by the President on May 21, 2009, and by the Vice President by telephone on Sunday, May 24, 2009. I have also had numerous phone conversations with different groupings of the individuals listed above. Other individuals have at times participated in these conversations, including Trevor Morrison, Associate Counsel to the President, Alison Nathan, Associate Counsel to the President, and Diana Beinart, Tax Counsel.