So it occurred to me that maybe this project should have been originally posted here instead of the Political Geography and Demographics board; I may ask for it to be moved/merged here. For the past week, I have been constructing this margin map and have now managed to go back all the way to 1980. I originally planned to go to 1992 or 1996 but I am now addicted to it!
Presumably, I'm going to continue back in time until I begin to run into a lot of county discrepancies (county boundary changes in the form of new or no-longer existing counties; I've already ran into this with 2 cities in VA and Broomfield County, CO, but that's it so far).
I'm working on a major project at the moment: animating modern presidential election results by county (by margin) into a GIF. Currently, each frame is one year and one second = four years.
The change in margin between two presidential elections is averaged out and split across three additional frames (years in between the two elections) to create an animated effect. So for instance, a county that was +12 Dem in 2004 and +24 Dem in 2008 would be +15 Dem in 2005; +18 in 2006; +21 in 2007.
Thus far, I have completed 1972-2012.
1972 to 2012