Barack Obama’s selection of Sonia Sotomayor to replace David Souter as Supreme Court justice has already set off a fierce response from conservatives and the Republican Party. Sotomayor would be the first Hispanic justice and only the third woman to serve on the nation’s highest court. The Republicans are sure to attack Sotomayor for various reasons even though she was first appointed to the bench by George H.W. Bush and confirmed by some of the more rabidly conservative Senators, including Jesse Helms and Rick Santorum. Glenn Greenwald lays out some of the likely attacks here. But what is the significance of Obama’s decision?