My assessment: In replacing O'Conner, Williams, Clement, or Callahan would move the court to the left. Jones or Batchelder would hold or move to the right.
And, the court has already been moved to the left in all likelihood with the appointment of Roberts to replace Rehnquist.
How can the Republicans expect the base to care who is elected or bother voting unless Bush keeps his promise to appoint Scalia-like originalists?