Your source please? Because this is what he wrote in 2008:
McCain for President
By Charles Krauthammer
Friday, October 24, 2008
Contrarian that I am, I’m voting for John McCain.
From http://www.washingtonpost.com/wp-dyn/content/article/2008/10/23/AR2008102302867.html
What else is he going to say publicly? He wanted to keep his Fox job. Sarah Palin was just too icky for him to support. Jerk.