The Senate Social Network

Social network analysis has been around since long before MySpace, Facebook, or the modern Internet itself. But the ubiquity of these platforms makes representations of data as social networks more familiar and accessible to readers. For example, here's a representation of the Senate as a social network, in which any two senators are "friends" if they vote the same way at least 65 percent of the time.

The math behind social networks borrows a few things from physics, beginning with a spring system that gradually resolves into a coherent picture, as you can see in the animation. While the nodes are colored according to the senator's party for visual effect, the network itself has no knowledge of partisanship. The divide is a natural consequence of a highly partisan legislature.