R.I.P. Chief Justice William Rehnquist

October 1, 1924 -- September 3, 2005

Born in Milwaukee, Wisconsin, he went on to receive masters degrees in political science from Stanford in 1949 and Harvard in 1950, and then graduated first in his class from Stanford law school in December 1951 (O'Connor graduated third in the same class, and they briefly dated each other while there). He went on to private practice in Phoenix (as an aside, O'Connor also came to Arizona after law school, where she served in the state legislature and as a state judge), and then became Assistant Attorney General. On the Burger Court, he was the most conservative member, earning the nickname "the lone ranger" for his frequent dissents; however, he was also regarded as the justice with the most impressive intellectual ability. As Chief Justice, he was widely respected, both in legal circles and on his own Court (some justices bristled under the Burger's administration of the Court). In about a two month period, Arizona went from having a claim to two justices on the Supreme Court, to having claim to none.

Appointed to the Court as Associate Justice by Richard Nixon (October 22, 1971; confirmed 68-26 December 10, 1971; took oath of office January 7, 1972)
Elevated to Chief Justice by Ronald Reagan (June 17, 1986; confirmed 65-33 September 17, 1986; took oath of office September 26, 1986)

Only five justices served longer than he did:
William O. Douglas
Stephen Field
John Marshall (Chief Justice)
Hugo Black
John Marshall Harlan (apparently destined for the court from the time he was named)
(He served briefly longer than Joseph Story, though that's because Story didn't take the oath of office until two and a half months after beiong confirmed by the Senate)

He is the first justice to die in office since Robert H. Jackson died on October 9, 1954, and the first Chief Justice to do so since Fred M. Vinson died September 8, 1953.

There are currently two vacancies on the Court (some would argue whether O'Connor's seat is really vacant, but I'll leave that aside) for the first time since Rehnquist was a nominee of Nixon (Powell was confirmed four days before him, but they took the oath of office the same day).

As for a possible replacement, I doubt that Bush will elevate a current member of the Court; he will more likely look outside the Court for a new Chief (it may sound odd to do so, but only four chief justices have reached that position via promotion within the Court, and all in the 20th Century (though John Rutledge was recess appointed to the Chief Justiceship after having resigned as an associate justice, and his permanent appointment to the post was rejected by the Senate, and Abe Fortas was nominated for the Chief Justiceship, but his nomination was withdrawn when it became evident that he would be defeated in the Senate)). Look at the previous list of candidates that I provided for O'Connor; it will probably be one of them.