This morning I was greeted with a spectacular display of information that I found at the same time beautiful, educational, and awe-inspiring.
Ladies and Gentlemen, may I direct your attention to this most arresting visual display:
Only a portion of the image is provided here, and in reduced size, for copyright reasons; click on the image or here for the full poster-size version. Full documentation and methodology is incorporated within the poster.
Without even going to the full image, you can clearly see the great swings caused by the Depression and the Civil War... and you can see the influx of the far-right into Congress in recent years. But I spent quite a bit of time looking over the full-sized poster, and I encourage everyone else to as well. From one perspective, it's a wonderful example of embedding information in an image, and from another it's a grand view of our American history and government.
P.S. I also highly recommend the web comic this is posted on, http://www.xkcd.com , but it's not generally political.