From the Atlantic two weeks ago:
Three of the five Justices in the majority — John Paul Stevens (age 88), Ruth Bader Ginsburg (age 75) and David Souter (age 68) — are widely expected by court observers to retire or otherwise leave the Court in the first term of the next President. By contrast, the four judges who dissented — Antonin Scalia, Clarence Thomas, John Roberts and Sam Alito — are expected to stay right where they are for many years to come.
John McCain has identified Roberts and Alito as ideal justices of the type he would nominate, while Barack Obama has identified Stephen Breyer, David Souter and Ginsberg (all in the majority today). It’s not hyperbole to say that, from Supreme Court appointments alone, our core constitutional protections could easily depend upon the outcome of the 2008 election.
Another Republican cannot be allowed in the White House. Saving the Supreme Court and, with it, the Bill of Rights, is more important than getting out of Iraq.
That’s a red herring, a Supreme court justice will have to be approved by the Democratic senate, so you are very unlikely to get a judge who would vote against Roe v. Wade etc etc
Only two justices appointed by Democrats are left. Do you really want a Supreme Court even more unbalanced than the one we have now?
Obama was a constitutional law professor. He knows the constitution. And how refreshing would it be to have a court that understands the constitution?