National Average Trending: An Incredible Waste of My Life

[ElectionAtlas]

Alcon,
how did you calculate your percentages?  If I look at Snohomish County, I have a margin in 2004 of 7.50 in 2004 (+ = Dem) and 7.96 in 2000 for a net shift to Republican of 0.46, not a shift to the Democrats.

Here is my auto-generated map
<5, < 10, < 15, < 20, > 20 as my color coding.

[ElectionAtlas]

Overall looks good.  I created the normalized (to national margin change) swing maps for all states as well.  Alcon - check Franklin/Walla Walla - the generated map has them reversed from your map.  Hope that I didn't take away any fun... great idea - if anyone has others, I have scripts that can generate county-level maps based on my blank templates.
Dave

[ElectionAtlas]

I figure we'll bounce this around a bit before I mass-produce maps and data for previous years.  The current algorithm is
swing: (voteD1 - voteR1)/TotalVote1 - (voteD2 = voteR2)/TotalVote2. 
trend: (voteD1 - voteR1)/TotalVote1 - (voteD2 = voteR2)/TotalVote2) - ((voteDnational1 - voteRnational1)/nationaltotalvote1 - (voteDnational2 = voteRnational2)/nationaltotalvote2)

Minor parties will influence these meaning of the trend/swing figures - although even in the Case of Ralph Nader, its not obvious that all the votes would have gone Democratic -> how many would not have bothered to vote at all?  How many would have voted for Bush? How many for Badnarik?  (I've seen data in NH that more Bush voters cast ballots for Nader than Kerry voters).   

I think that "third party" votes are another level of analysis that can be performed when considering vote swings ant trends (there are maps for third-party strength already).
Enjoy,
Dave