This article at the New York Times (via Drudge) describes Bush’s selection process via the testimony of one of the candidates, plus insider reports.
Judge Wilkinson’s conversation with the president about exercise and other personal matters in an interview for a job on the highest court in the land was typical of how Mr. Bush went about picking his eventual nominee, Judge John G. Roberts, White House officials and Republicans said. Mr. Bush, they said, looked extensively into the backgrounds of the five finalists he interviewed, but in the end relied as much on chemistry and intuition as on policy and legal intellect.
“He likes to have the info, he likes to have the background, but he also is a field player,” said Dan Bartlett, the counselor to the president, in a briefing to reporters on Tuesday night. “He likes to size people up himself, make his own judgment.”