Obama won't be able to replace Scalia with a justice as liberal as Sotomayor

Besides the election, the other big hurdle facing Obama is that Scalia was a conservative cornerstone of the court. Sotomayor and Kagan, by contrast, were replacing two liberal justices. The potential to change the ideological tilt of the court would likely lead to high interest-group opposition from anti-abortion groups among others. Charles M. Cameron and Jonathan P. Kastellec of Princeton University and Jee-Kwang Park of American University have argued that interest groups play a key role in determining whether a nominee is opposed vigorously by a party that does not hold the White House.

If Obama does make a nomination, what type of nominees should he consider? Not surprisingly, the model indicates that more moderate and better-qualified nominees would have an easier time being confirmed. Ruth Bader Ginsburg was very well-qualified, and even though she was a mainstream Democrat, she was nearly unanimously confirmed. My guess is that in the current hyper-polarized Congress, a nominee like her wouldn’t come close to the vote total the model suggests for a well-qualified mainstream Democrat, but she’d stand a chance.