States are sorted by party preference in an exponentially-decaying manner, that is 1 for a “D” in 2008, plus 0.8 for a “D” in 2004, plus 0.64 for a “D” in 2000 . . . a sort order intended to emphasize how consistently a State has gone for whichever party in recent years. For the benefit of the color-blind, to avoid adding a key, and to simplify the handling of third parties I kept the party letters.

The problem with so many of the red and blue graphics we’ve seen over the past few months, and with the first and third charts in your post, is that the intensity of the red and blue jumps at me, and I have to squint before I can make sense of them. When there is a whole huge area of red and blue blocks or shapes, it’s hard to focus on the message.

Your middle chart is a great reminder that sometimes we want to focus on a subset of the data. The third chart was a good first attempt at showing the sign of the change. I think it could be made less intense if instead of filling the entire cell with the bright color, you used a dot of that color, much like the green dots in your second chart.

What I like about the third chart is that you could easily scan a page, and see that some years (1972, 1980) were major swings to the right, and other years (or year, 1976) were swings to the left. This would not be visible in the first chart.