John Paul Stevens

For only the second time since 1939, the Supreme Court seat held by Associate Justice John Paul Stevens is coming open. Stevens announced today that he plans to retire at the end of the Court's current term. He had telegraphed his intention well in advance, so no one is surprised by his retirement.

Stevens, 89, was nearing records for being both the oldest and the longest-serving Supreme Court justice in history. He has made clear that his longevity on the Court has not been based on an ambition to break those records.

The oldest justice was Oliver Wendell Holmes, Jr., who was 90 years old when he retired in 1932. Stevens would have surpassed that mark, had he stayed on the Court into the early months of 2011.

The longest-serving justice was William O. Douglas, Stevens's predecessor, who was appointed by Franklin Roosevelt in 1939, and retired in 1975. That was when President Gerald Ford appointed Stevens as an associate justice. Stevens would have broken that record in 2012.

For the second consecutive year, President Obama will appoint an associate justice. As was the case with David Souter's 2009 retirement, the atmosphere in Washington will be slightly less heated than it might otherwise be, because Stevens, although he was appointed by a Republican president, is classified as being part of the Court's liberal wing. Therefore an Obama nominee will not be expected to change the ideological balance among the justices.

However, as we saw with the nomination and confirmation of Justice Sonia Sotomayor last year, there is no longer any such thing as a non-controversial Supreme Court appointment. I doubt that the Senate's unanimous confirmation of Stevens's appointment will be repeated for his successor.