Have to give props here to Paul Ciszek on AFCA, who notes "Math is a tool of the Liberal Media". http://groups.google.com/group/alt.fan.cecil-adams/browse_frm/thread/0dcdcc0bc84e5cda?hl=en
The writeup is on Wonkette:
The original data comes from some source called "Opinions" (truth in labeling, that). The graphic is from Fox News, although that's pretty easy to guess.
It's always a good guess that anything displayed as a pie chart has been assembled by someone who has little or no understanding of statistics, because a pie chart is usually a poor choice for displaying data -- one of the few worse choices is a 3-D pie chart.
For this type of data, a pie chart can be used, but not if you are going to have percentages that add up to 193%. The lack of a "don't know" or "by God, isn't there somebody else we can get?" category is also disturbing.