This is an interesting diagram because it illustrates how objective information can be displayed in a manner that influences your perception of the data.
In the first three vote blocks, the dividing line between “Yay” and “Nay” is drawn in the middle of the “split” party, indicating there are party members on both sides of the debate. However, in the final vote block on Heathcare Reform, the creator of this diagram has specifically arranged the colors such that the Yay/Nay dividing line runs directly between the parties, with the dissenting Democrats hidden off to the right side. Thus, the Heathcare Reform vote appears more partisan and divisive than it actually was.
(diagram via shaunbwilson, from www.politicalmathblog.com)
Source: politicalmathblog.com
