Obama's Potential Impact on the Supreme Court

The New York Times: To Nudge, Shift or Shove the Supreme Court Left, by Adam Liptak:

...The vacancies that are likely to open up in the early years of the Obama presidency will, if the conventional wisdom holds, arise from the retirements of one or more of the court’s liberals — Justice Stevens, Justice Ginsburg or Justice David H. Souter. 

If that is so, Mr. Obama will not be able to put a new liberal vote on the court. But he can, if he wants to, add a big liberal voice....

According to a study last year by William M. Landes, who teaches law and economics at the University of Chicago, and Judge Richard A. Posner of the federal appeals court there, four of the five most conservative justices to serve on the court since 1937, of a total of 43, are on the court right now: Chief Justice John G. Roberts Jr. and Justices Scalia, Clarence Thomas and Samuel A. Alito Jr. The fifth was Chief Justice William H. Rehnquist, whom Chief Justice Roberts replaced in 2005.