At 90, Stevens is the oldest and the longest-serving member of the current Court. He is also considered the leader of the Court's liberal bloc. His retirement gives President Obama the chance to make his second appointment to the Court; his first was Justice Sonia Sotomayor, who joined the Court last summer.
"The ideological leaning of the Court won't change dramatically; he was a liberal and President Obama will appoint a liberal to replace him," says Jeffrey Rosen, a law professor at George Washington University.
Aside from Stevens, four other Justices are over 70 , so it's possible that this won't be Obama's last chance to make a Supreme Court appointment.
Stevens was appointed in 1975 by President Gerald R. Ford, a Republican, who said all he wanted was "the finest legal mind I could find." In that sense, Stevens is a vestige of a time when ability and independence, rather than perceived ideology, were viewed as the crucial qualifications for a seat on the high court. Nineteen days after he was nominated, and after only five minutes of debate, the Democratic-controlled Senate confirmed Stevens, a Republican, by a vote of 98-0.
Don't expect anything so civilized this time around. In recent decades, the confirmation process has become a months-long ordeal. Nominees are carefully screened by the White House, and then grilled on live TV by Senators about their views, private lives, and anything they've written. The intense scrutiny means that it's much less likely that an appointee will turn out to be a surprise. But it's not impossible.
"You never know how one person can end up moving a Court," says Lee Epstein, a Northwestern University law professor. "The Justices change, the times change, the cases change."
When Stevens joined the Court, he was considered a moderate. He has said repeatedly that his beliefs haven't changed, but that the Court has shifted, becoming more conservative in recent decades. But others say Stevens has also changedunderscoring the point that a President can never know for sure what kind of Justice his choice will turn out to be.
(President Dwight D. Eisenhower learned that the hard way with his appointment of Earl Warren, the Republican Governor of California, as Chief Justice in 1953. Warren was much more liberal than Eisenhower expected, leading the Republican President to later call his appointment of Warren "the worst damn fool mistake I ever made.")
Gun Control & Free Speech
Stevens's departure means the Court could be without a Protestant, the nation's majority religionsomething that would have been unimaginable a generation ago. (Aside from Stevens, there are six Catholics and two Jews on the Court.) Stevensa World War II veteranis also the last remaining Justice to have served in the military.
The Supreme Court heard major cases this term dealing with First Amendment issues on campaign-finance regulation, and Second Amendment issues on gun control. Both issues are likely to return to the Court in the next few years.
Other big issues that are likely to come before the Court include the extent of the President's power in fighting terrorism, the rights of detainees, the constitutionality of the health-care overhaul that the President just signed into law, and of same-sex marriage, affirmative action, and a host of Internet-related privacy and free-speech issues.
Stevens says he hopes his successor is confirmed "well in advance of the commencement of the Court's next term," which starts, as always, the first Monday in October.
That may happen, but getting there could involve months of intense debate. "Both sides are so set up to have a battle that it will exist almost regardless of who's nominated," says Rosen.
Aside from the politics of an election year, the stakes are so high because Supreme Court Justices serve for life.
"Presidents recognize that Justices of the Supreme Court serve long beyond their own terms, so it's one of the ways they can have an impact 20 years after they leave office," says Geoffrey Stone, a law professor at the University of Chicago.
But as Neil Richards of Washington University in St. Louis points out, "The downside of appointing someone young is that you don't quite know what you're going to get, since people tend to change their views as they age."
(The New York Times Upfront, Vol. 142, May 10, 2010)