The Reality-Based Community

 Percentages

Obama campaign talking point :

If Governor Palin and John McCain want to define 'change' as voting with George Bush 90% of the time, that's their choice, but we don't think the American people are ready to take a 10% chance on change.

This is the wrong way to look at it. A McCain administration would be like Bush's 90% of the time. A (gulp) Palin administration (conditional probability 20%, said unrefuted Mark) would be like nothing you'd ever seen before.