Guest from Sanity,
There is one big difference between the Bush/Cheney administration and the would-be McCain/Palin administration, on the one hand, and the Clinton/Gore administration and the Obama/Biden administration, on the other:

SCOTUS -- and the other Federal Courts.

Gerald Ford appointed John Paul Stevens. Ronald Reagan appointed both Antonin Scalia and Sandra Day O'Connor, Herbert Walker Bush appointed David Souter and Clarence Thomas, and Bill Clinton appointed Stephen Breyer and Ruth Bader Ginsberg. (Not sure GHWB knew just how reactionary Thomas was going to be, since Thomas refused to talk about his views, even during his Senate confirmation hearings.) Bush 43 appointed John Roberts and Samuel Alito -- both of whom have shown themselves to be further to the extreme Right than even Rehnquist and Scalia on some decisions.
McCain has explicitly stated that he would not appoint Ginsburg, Breyer, Stevens, OR Souter or Justices like them if he becomes President.   He has said that he would appoint people like Scalia, Thomas, and Roberts.
There is no way that Obama would select Justices like those. In fact, he has said Clarence Thomas is the Justice he would most like to not have on the SCOTUS.

The Supreme Court and other lifetime Federal Court appointments are going to have a much longer-lasting impact on all aspects of our domestic and international policy and on our economy than any legislation from Congress or Presidential executive order will have.

And I think if the Democrats fail to hit that point home to the "undecided" voters and the persuadable, teachable Republican voters, it may be their downfall.   They need to spell out exactly how the composition of the courts are likely to affect things like reproductive choice rights, bankruptcy laws, people's right to sue for just compensation when wronged, freedom of expression, freedom from unreasonable search and seizure, etc.