With Sen. Arlen Specter grabbing the headlines yesterday with his party switch, here are two cool interactive visualizations that show the ‘topography’ behind the senator’s dramatic move.

The first one comes from two political science Ph.D. students at the University of Michigan who write the Computational Legal Studies blog. It’s a view of where Specter sits in terms of the campaign finance environment in relation to all other senators during the 110th Congress.  The visualization allows you to zoom in and read the labels on large institutional givers and the senators they made contributions to. You’ll see that Specter is closer to the Democrats than the Republicans in this visualization.  Here are the overall Senate and the House version. And here’s the visualization of industry giving to senators.

Another very cool visualization comes from Slate, where they present the Senate as a “Facebook-style” social network. Slate’s visualization clearly demonstrates how Specter and the vast majority of his former GOP senatorial colleagues kept each other at arm’s length. Slate connects senators who vote together 65 percent of the time. By playing around with the visualization you will see that most senators hang tight with the lawmakers from their own party. Specter is one of four that “float” between the two-party masses, Olympia Snowe and Susan Collins from Maine and Ben Nelson from Nebraska.

Super visualizations like these are one of the more interesting and most illustrative ways to open up government data so anyone can figure out what is really going on.