John Sides of the Washington Post recently discussed the way that political maps illustrate the divide over political opinions — noting that some of the real life diversity of opinion is lost in all the red and blue. “Most of us live in a purple America, not a red or blue America,” said Sides. Then, in a flurry of color, he reveals what one researcher has made of your average political map. It’s a more patchy and blended one, and it reveals the true complexity of political opinion in a unique ways.
Nate Cohn, a self professed cartography enthusiast with the New Republic, points out that in maps of the U.S. that are divided between blue and red states, you start to lose sight of some of the more important details involved. It may look like the U.S. is largely a Republican country based on a black and white — or in this case — red and blue map that labels each state like an on off switch with no middle ground. However, when you take into consideration the populations of each state and counties, it becomes clear that the size of a state can be misleading as to the political partisanship of actual individuals.
By district, the Republican lead is even more misleading. Cohn and Sides both reference a series of maps created by Mark Newman, from the department of physics and the center for the study of complex systems at the University of Michigan.
Cohn explains that Newman’s maps — or cartograms — are ones in which “the area of spaces on a map is determined by a variable other than geographic area. In this case, it’s population: Make the most populous counties proportionately larger than the least populous counties,” explained Cohn. What ultimately happens is a major distortion of our normal view of red and blue within the U.S.
“Notice just how many Americans live in a handful of counties, like Los Angeles, Cook (Chicago), or in the New York City area, or how the high planes are reduced to a compressed series of lines,” said Cohn. Newman was making a point beyond this, and one echoed by both Cohn and Sides, which is that even a catrogram that reveals something about population doesn’t show how much of a mix each state has politically.
Even states with a majority of Republicans or Democrats may have nearly as many opposing members — but a map such as we usually see will simply tell us that this county or state is Republican only. That’s where Side’s discussion of purple comes in — and where another cartogram from Newman becomes relevant.
By adding shades of purple to show the percentages of votes, as well as reds and blues, the map is improved to “reveal more nuance in the vote,” according to Newman. It also is transformed to show population, distorting the shape of the country, but revealing its proportions better, and adding another layer of detail.