Mapping Partisan Sorting in America

Partisanship in Chicago, Dallas-Fort Worth, Los Angeles and New York (New York Times)
The New York Times

The New York Times maps partisan sorting in America—the tendency for voters to self-select into areas where people think and vote the same way they do—down to the neighbourhood level.

The maps above—and throughout this article—show their estimates of partisanship down to the individual voter, colored by the researchers’ best guess based on public data like demographic information, voter registration and whether voters participated in party primaries.

We can’t know how any individual actually voted. But these maps show how Democrats and Republicans can live in very different places, even within the same city, in ways that go beyond the urban-suburban-rural patterns visible in aggregated election results.

It goes beyond racial, urban vs. suburban vs. rural and house vs. apartment splits, to the point where researchers are wondering whether Americans are “paying attention to the politics of their neighbors” when they decide where to live. This has implications not only in terms of electoral targeting (e.g. gerrymandering, voter suppression), but in terms of basic social cohesion.

The maps are based on research by Jacob R. Brown and Ryan D. Enos published earlier this month in Nature Human Behavior.

Previously: Red and Blue vs. Gray and Green.

COVID-19 in Los Angeles

New York Times (screenshot)

The New York Times maps the distribution of COVID-19 cases in Los Angeles. “County officials recently estimated that one in three of Los Angeles County’s roughly 10 million people have been infected with Covid-19 since the beginning of the pandemic. But even amid an uncontrolled outbreak, some Angelenos have faced higher risk than others. County data shows that Pacoima, a predominantly Latino neighborhood that has one of the highest case rates in the nation, has roughly five times the rate of Covid-19 cases as much richer and whiter Santa Monica.”

Mapping Climate Risk in the United States

The New York Times (screenshot)

Climate change isn’t just one thing: rising temperatures, or sea level rise. It’s also changes to rainfall, increased risk of wildfires, more powerful hurricanes. The extent to which any of these are threats depends on where you live: North Dakota doesn’t have much to worry about rising sea levels, but it should think about drought. That’s what this interactive map from the New York Times attempts to measure: the climate risks to the United States on a county-by-county basis.

Previously: How Climate Change Will Transform the United States.

Mapping the Coronavirus at U.S. Colleges

Colleges with coronavirus since the pandemic began (NY Times)
The New York Times

The New York Times maps COVID-19 cases at U.S. colleges and universities. The map and searchable database are based on their survey of more than 1,600 post-secondary institutions; the survey “has revealed at least 88,000 cases and at least 60 deaths since the pandemic began. Most of those deaths were reported in the spring and involved college employees, not students. More than 150 colleges have reported at least 100 cases over the course of the pandemic, including dozens that have seen spikes in recent weeks as dorms have reopened and classes have started.”

Red and Blue vs. Gray and Green

New York Times

The New York Times uses the colours in aerial images as a proxy for political leanings: rather than red-and-blue electoral maps, the political landscape, Tim Wallace and Krishna Karra argue, is more green and gray.

The pattern we observe here is consistent with the urban-rural divide we’re accustomed to seeing on traditional maps of election results. What spans the divide—the suburbs represented by transition colors—can be crucial to winning elections. […] At each extreme of the political spectrum, the most Democratic areas tend to be heavily developed, while the most Republican areas are a more varied mix: not only suburbs, but farms and forests, as well as lands dominated by rock, sand or clay.

This is a generalization, to be sure, but so are most political maps, and the notion that urban areas tend to vote Democratic while rural areas tend to vote Republican isn’t what I’d call a revelation. Still.

Mapping Mask Wearing in the United States

The New York Times (screenshot)

Wearing a mask in public is increasingly being encouraged or required as a measure to slow the spread of COVID-19. The New York Times maps the rate of mask wearing in the United States. The county-level map is based on more than 250,000 responses to a survey conducted in early July, in which interviewees were asked how often they wore a mask in public.

The map shows broad regional patterns: Mask use is high in the Northeast and the West, and lower in the Plains and parts of the South. But it also shows many fine-grained local differences. Masks are widely worn in the District of Columbia, but there are sections of the suburbs in both Maryland and Virginia where norms seem to be different. In St. Louis and its western suburbs, mask use seems to be high. But across the Missouri River, it falls.


How to Make an Illustrated Map

Five Squares + One Triangle in My Neighborhood (Nate Padavick)
Nate Padavick (The New York Times)

In the travel section of yesterday’s New York Times, map illustrator Nate Padavick offers a way to make lemonade from travel-restriction lemons with a short guide to making an illustrated map (pictorial map, map illustration—the terms are roughly interchangeable) of a favourite place—a neighbourhood, a vacation spot, “a place you’ve never been.”

The rigid and scientific rules of cartography simply do not apply here! Nope. While an illustrated map is often a wildly useless tool for providing directions, it can be a beautiful and highly personal reflection of a place you, friends and family know quite well. It can tell a story, a personal history, or be a unique lens through which one can experience a special place. An illustrated map can be loose and hand-drawn, filled with fun drawings and doodles that together make a sometimes inaccurate, but always spot on record of a memory or a place from one’s own perspective.

Not the first time we’ve seen map art as lockdown activity. Previously: Maps from Isolation; CityLab Wants Your Hand-Drawn Quarantine Maps; Still More Coronavirus Maps; Fuller’s Quarantine Maps.

A Naïve Look at New York’s Subway Map

Screenshot (

The New York Times does a deep dive into New York’s current subway map: its design choices, its history, its quirks. It’s more an animated slideshow than interactive map: each step takes us along a route, bouncing up and down (for example) where you’d expect to walk. It’s also completely devoid of any context, particularly the controversies around this very map’s design. People have been agitated about New York’s subway map, and have been reimagining and rethinking it, for decades.

That said, even a naïve look at the status quo isn’t without value, especially since the status quo is rarely looked at on its own terms, but rather in the context of tearing it up and coming up with something new and better.

The New York Times Maps Democratic Donors

The New York Times

In a series of maps, the New York Times explores where the donors to the various Democratic candidates for U.S. president live. The maps are based on data to June 30, and include donations of $200 or more. Bernie Sanders has by far the most donors so far, and they’re distributed broadly, so the second map on the page excludes Sanders donors to tease out where other candidates’ donors are concentrated regionally.

Measles in America

The New York Times (screenshot)

The New York Times maps confirmed measles cases in the United States as of April 29, 2019. “Measles was declared eliminated in the United States in 2000 but the highly contagious disease has returned in recent years in communities with low vaccination rates. The number of cases reported this year is already nearly double last year’s count and has surpassed the previous post-elimination high of 667 cases in 2014.”

Mapping the Sulawesi Earthquake and Tsunami

The New York Times (detail)

Last week a magnitude-7.5 earthquake struck the Indonesian island of Sulawesi, triggering a tsunami that struck the city of Palu with far more force than expected. The New York Times has multiple maps and aerial images of the damaged areas; NASA Earth Observatory has before-and-after Landsat imagery.

‘Empty Land Doesn’t Vote’ and Other Hot Takes

New York Times (screen capture)

The hot takes about the New York Times’s detailed map of the 2016 U.S. presidential election results (see previous entry) have been coming in fast. Most of the critiques focus on the map’s failure to address population density: a sparsely populated but huge precinct appears to have more significance than a tiny district crowded by people. See, for example, Andrew Middleton’s post on Medium, Keir Clarke’s post on Maps Mania or this post on Wonkette—or, for that matter, a good chunk of cartographic Twitter for the past few days. (It’s not just Ken, is what I’m saying.)

The responses to those critiques generally do two things. They point out that the map had a specific purpose—as the Times’s Josh Katz says, “we wanted to use the 2016 results to make a tool that depicted the contours of American political geography in fine detail, letting people explore the places they care about block by block.” As he argues in the full Twitter thread, showing population density was not the point: other maps already do that. Others explore the “empty land doesn’t vote” argument: Tom MacWright thinks that’s “mostly a bogus armchair critique.” Bill Morris critiques the “acres don’t vote” thesis in more detail.

Relatedly, Wired had a piece last Thursday on the different ways to map the U.S. election results, in which Ken Field’s gallery of maps plays a leading role.

Previously: The New York Times’s Very Detailed Map of the 2016 U.S. Presidential Election.

The New York Times’s Very Detailed Map of the 2016 U.S. Presidential Election

New York Times (screen capture)

It’s 2018. The 2016 U.S. presidential election is nearly two years in the past. But that didn’t stop the New York Times from unleashing a new map of the 2016 election results earlier this week. On the surface it’s a basic choropleth map: nothing new on that front. But this map drills down a bit further: showing the results by precinct, not just by county. The accompanying article sets out what the Times is trying to accomplish: “On the neighborhood level, many of us really do live in an electoral bubble, this map shows: More than one in five voters lived in a precinct where 80 percent of the two-party vote went to Mr. Trump or Mrs. Clinton. But the map also reveals surprising diversity.”

Kenneth Field has some objections to the map. “So you have smaller geographical areas. Detailed, yes. Accurate, certainly. Useful? Absolutely not because of the way the map was made.” It’s a choropleth map that doesn’t account for population: “An area that has 100 voters and 90 of them voted Republican is shown as dark red and a 90% share. Exactly the same symbol would be used for an area that has 100,000 voters, 90,000 of whom voted Republican.” It gets worse when that thinly populated precinct is geographically larger. (Not only that: the map uses Web Mercator—it is built with Mapbox—so Alaska is severely exaggerated at small scales.) There are, Ken says, other maps that account for population density (not least of which his own dot density map).

The Times map has a very specific purpose, and Ken is going after it for reasons that aren’t really relevant to that purpose. The map is aimed at people looking at their own and surrounding neighbourhoods: the differences in area and population between a precinct in Wyoming and a precinct in Manhattan wouldn’t normally come up. It works at large scales, whereas Ken’s point is more about small scales: zoom out and the map becomes misleading, or at the very least just as problematic as (or no more special than) any other, less granular choropleth map that doesn’t account for population. The map isn’t meant to be small-scale, doesn’t work at small scales, but then people regularly use maps for reasons not intended by the mapmaker. The mistake, I suspect, is making a map that does not work at every scale available at every scale.

Update: See this post for more reactions to the map.