A blank map of all of the U.S. congressional districts (as of the 110th Congress)
Based off of: File:US House Winning Margins Runoff.png for most boundaries, [1] for Georgia, and [2] for Texas.
File:US House Winning Margins Runoff.png: Marcus Graly
derivative work: Mr. Matté (if there is an issue with this image, contact me using this image's Commons talk page, my Commons user talk page, or my English Wikipedia user talk page; I'll know about it a lot faster)