Four years ago, Daily Kos Elections introduced a map of United States congressional districts that showed each district with the same area in order to more accurately describe the distribution of political power in the House. Every district sends just one representative to Congress, so our map accurately balanced large rural districts and small urban districts—no more sea of sparsely populated red obscuring densely populated blue. After all, land doesn’t vote.
Now, it’s time for an upgrade! The example above shows the population density of each district. (For a full size map, click here, and for templates you can use to make your own maps, click here.)
The Good News
The most immediately obvious change: Every state’s shape is now preserved as we are used to seeing it on an ordinary map.
Because the states are kept in their original shapes but are also scaled by the number of their congressional districts, they no longer fit together snugly and so are no longer adjacent to each other. This leaves room for state labels.
This also means the states of the Intermountain West do not need to be adjacent to any neighbor, and can be placed in their approximate locations on a standard map. Think of it as life slowly returning four years after the eruption of the Yellowstone supervolcano.
In addition, many smaller states now have districts that can be more accurately placed within the state, since they are not smooshed by the larger states surrounding them. (Some fare worse: We’re really sorry, Michigan.)
In a separate version, we’ve also included for the first time the territories that send nonvoting delegates to Congress. See an example to the side and a full-size map here.
All this results, we hope, in a more elegant, more familiar, and easier-to-interpret map.
The bad news
There are, as always, some trade-offs—but ones we obviously think are worth it. First, the states are no longer contiguous, which can make it harder to assess the total area of a given color.
The districts are also no longer exactly equal in area. But with just two major exceptions, they are within about 10% of the ideal. Those exceptions are the districts of Hawaii, where HI-01 is too small and HI-02 is too large, although it’s not particularly noticeable. (We made the choice not to slice off a part of the island of Hawaii itself to add to HI-01 or change the scale of individual islands.)
The biggest trade-off, though, is that districts sometimes cannot be placed within states where you’d expect them to be geographically. For instance, the districts that make up New York City all appear to live in upstate New York in our map—there just isn’t enough room to fit them all in the NYC area.
And there’s really no way around this if you want the states to remain recognizable and retain their shapes. The only alternatives would be to badly distort state outlines (yielding something like this) or to use a traditional map (which has its own problems, as we illustrate below).
Finally, because this version has more white space, each district is a little smaller relative to the map as a whole than in the original version.
Don’t worry, though—if you prefer the original version, you can still find it here.
Why we use cartograms
Why do we bother with this kind of map, called a cartogram? We discussed this at length when we introduced our original version, but the map at the top of this post provides another opportunity to showcase its usefulness. Here’s the same information, displayed on an ordinary map of the lower 48:
You can immediately see that the least-dense districts dominate the map. The 150 districts with the greatest population density (the darkest two shades) are either completely invisible (the most dense) or small, tangled, uninterpretable blotches. In other words, approximately one third of the country’s population is erased in a standard map of congressional districts. Our cartogram neatly resolves this problem.
The Electoral College
As a companion to this new congressional map, we’ve also updated our Electoral College map in the same style. (We had to be a little creative in placing New Jersey and the District of Columbia, otherwise the whole thing looked like a fat llama.)
Free to Use
The best part is that these maps, as always, are free for you to download and use as long as you cite us as your source and link back to the source files. We have shapefiles, image files, and SVG files available. The Electoral College Map and Congressional District Map by Daniel Donner for Daily Kos Elections are licensed under a Creative Commons Attribution 4.0 International License. Please provide a link to https://dkel.ec/map in any published material so that others may take advantage of these files as well. And happy mapmaking!
September 20, 2022: Version 3.0 released.
