> [I wonder if there would be a way to map this in a way that would be
> striking and clear. Perhaps by county?]
Here's a county-by-county map that does the blue/red thing: http://www-personal.umich.edu/~mejn/election/countymaplarge.png
There was a graphic on the front page of the S. J. Mercury News last Sunday illustrating this in the case of California--you might check their website and see if they've got a version on-line.
As for other mappings, it might be interesting to go down to the precinct level and look at, oh, some metropolitan areas and the counties touching them.
All the best,
John A
