THE PLANK DECEMBER 14, 2007
A lot! At least from the looks of this 'Hardball' clip (via Ezra Klein) featuring Edwards's Joe Trippi, Clinton's Mark Penn, and Obama's David Axelrod. The fireworks start at about the 4:00 mark.
It's especially interesting that Trippi seems to spend almost as much time defending Obama from Penn's attacks as he does boosting Edwards.