The official Etch-A-Sketch of the Rick Santorum campaign, etched during walk-off song of “Shake it up baby.” (Photo taken by Lindsey Boerma, CBS News and National Journal)

The official Etch-A-Sketch of the Rick Santorum campaign, etched during walk-off song of “Shake it up baby.” (Photo taken by Lindsey Boerma, CBS News and National Journal)