The Washington PostDemocracy Dies in Darkness

Presenting the least misleading map of the 2016 election

President Trump speaks during an interview with Reuters in the Oval Office of the White House on April 27, 2017. (Carlos Barria/Reuters)
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The fundamental tension in presenting the results of an election in a map is balancing geography with population. Maps generally depict geographic areas, and votes rarely conform neatly to geographic boundaries. We’re left considering maps of presidential election results, then, which in recent cycles have been broad swaths of red punctuated by the occasional blue splotch.

“Here, you can take that; that’s the final map of the numbers,” President Trump told Reuters reporters when they visited the Oval Office in spring 2017. He had helpfully provided copies of the map for the 2016 contest. “It’s pretty good, right? The red is obviously us.”

That map, pictured at the top of this article, looked something like this.

It’s imprecise for a lot of reasons, the most obvious and well known of which is that all of that red is mostly empty space.

After the 2016 election, researcher Ryne Rohla tried to build a better version of that map by drilling down further, picking out results, precinct by precinct. In March 2017, he published an interactive version of that map at Decision Desk HQ.

It looks like this.

This is better than the map above simply for the resolution. The broad swaths in that county map are here more like pixels, showing that the vast expanse of red is a bit more freckled than even that county map suggests. Look at California, for example: It’s a mess of liberal coastal areas and more conservative regions elsewhere in the state. To a large extent, the map above is a map of where America’s cities are, which, of course, is a map of where most Americans live.

Contrast that with the most important map of a presidential election: the results by state.

It’s this map that determines the winner, via the electoral college, but it’s also one of the least informative about what actually happened. That belt of blue votes running through the Deep South simply doesn’t exist, just as New York’s mostly Republican counties disappear into a dark blue.

This level of abstraction is usually as far as such maps are taken. But journalist John Cook raised an interesting point about the presentations on presidential maps.

That’s true. Hillary Clinton won the popular vote nationally. So at the other end of the precinct-level map lies this one.

It, too, lacks a great deal of information. But more than any of the other maps above, it does convey a critical buried detail: For all of Trump’s red on his county map, it’s the blue vote that carried the day. At least in vote totals.

From highest to lowest resolution, the results of the election look like this.

Of those four maps, the county-level map — the one Trump used — is perhaps the least informative. Unless we’re looking at data that isn’t conveyed well at other levels but moves beyond electoral or popular votes.

Consider this map, which looks at the change in voting since 2000. It shows that many of the counties that became more Republican from 2000 to 2016 (looking at voting margins relative to the national margin), the population declined. In places where the Democrats improved, the population often increased. Forty-four percent of counties that voted more Republican in 2016 than 2000 lost population. Seventy-nine percent of counties that voted more heavily Democratic increased in population.

That shift can also be displayed like this.

That’s the other problem with Trump’s map: All that red is not only mostly empty space, much of it is increasingly only empty land.

In the interest of accurately conveying the results of the election, we presume that the president will soon switch to Cook’s light-blue-only map. The image shared in this article should be high-enough resolution to print cleanly.