Friday 4 November 2016

The 435 Congressional Districts of the United States in one giant poster

In his last State of the Union Address, President Barack Obama called for an end to gerrymandering - the process of drawing political boundaries in a way that favours one party over another. I knew a bit about the topic from my time in the US, but I wanted to see what all 435 Congressional Districts looked like, so I ran off a set of maps. This was later picked up by WIRED* and shared quite widely. This week, I saw US elections guru Stephen Wolf had published a new shapefile of Congressional Districts which included the revised Florida, North Carolina and Virginia boundaries. I had a few extra moments due to something being cancelled at the last minute, so I ran off a set of maps and turned them into a gif and a poster. I shared the gif on twitter but am posting more material here in case anyone is interested. First of all, here's the massive poster with all 435 Congressional Districts, arranged alphabetically by state and District number.

Not to scale - it's about comparing shapes - bigger version

You should be able to click on the above image to see the labels more clearly. If you want to download a really gigantic version, have a look here for the 13MB, 16,527x16,841 pixel monstrosity. Shapes alone can't necessarily tell us whether an area is clearly 'gerrymandered' or not but it's fair to say that in some cases it's a pretty good sign!

I also created two gifs which animate through all 435 Districts at different speeds. The first one below is the one I previously shared on Twitter and the other one is a slightly slower version. The intention of the first was to leave just enough dwell time on each frame so that you can perceive the variety of shapes but also see all 435 in under a minute. In the second, I'm trying to allow more cognitive processing time.

It's supposed to be somewhat hypnotic

The first one is pretty fast, with only a tenth of a second for each Congressional District. The version below shows each District for half a second, so might be a little bit more useful but then again it takes longer to run through.

The definitive gerrymandering gif? Maybe not, but it's a quick summary

Here I have been experimenting with display techniques partly as a way of educating myself on an important subject but also partly to figure out what the best way of representing the data in an easily digestible way is. I also posted each of the individual frames from the gifs to a Google Drive folder in case anyone wants to use them.

I like the small multiple approach of the poster better in many ways because you don't have to wait to scroll through the images and also you can make visual comparisons between, say, frame 2 and frame 200 without having to wait for the gif to loop through to it. Also, you don't have to interact with it in the same way so I find it more accessible and actually made it this way so that it could be printed out as a large poster and used as a focal point for discussion and debate - which I think is one of the things maps can be very useful for.

Finally, here's the poster in two different colours. There's also a folder with all three versions in different sizes.

Does it look better or worse in green? Bigger version

A classier colour, I feel - bigger version

Here's the Obama 'gerrymandering' part - source

*The person who wrote that WIRED piece has since been 'moved on' owing to some sub-optimal journalistic practices but the piece remains online under an editorial note.