Politics | Analysis
September 8, 2017 at 4:20 PM
There are no perfect maps of presidential election results. There's always a balance between geography and vote totals that forces the designer to choose between making it recognizable and making it accurate. We've been over this ground before — everyone's been over this ground before — but this chart from our efforts in early August makes the point clearly.
It compares D.C., where Hillary Clinton did the best last year, with Roberts County, Tex., where Trump had the biggest margin of victory. Coloring the geography of each county would suggest that Roberts County carried more weight than did Washington but, electorally, it didn't.
If you want to convey an accurate balance between number of votes and vote margin, you end up with something that looks like this, created by M.E.J. Newman of the University of Michigan.
Accurate — but hard to recognize.
A few weeks ago, we explored a different set of data related to the election. Ryne Rohla reached out to every state and compiled precinct-level results from across the country. This has the advantage of giving a more finely-grained view of how the 2016 race turned out which, in turn allowed Rohla and the site Decision Desk HQ to create a map with much more refinement than a normal electoral map. This map:
Unfortunately, this map (which President Trump tweeted last month, naturally) still falls prey to the same problem of over-representing big places with few people. All that red in the middle of the country? Not actually a crowd of votes, just mostly empty territory whose scattered residents preferred Trump's candidacy.
We took Rohla's data and tried to correct for that, scaling the results in each precinct by the number of votes. That gives us a map that looks like this. (Click these images to view larger versions.)
This is still imperfect. After all, there are a lot of precincts in places like San Francisco that appear as a big cluster on that map. Here's a closer look at the Bay Area.
Same situation in New York City. Manhattan is so dense that it's just dot after dot after dot, which, on our national map, all sit over one another.
(By the way, notice those red dots in the bottom center of that map: Trump strongholds in Brooklyn, of all places.)
There is an interesting aspect to these maps, though. Check out Minneapolis.
Our color scale goes from red to white to blue, so the most hotly contested areas tend to fade into the background somewhat. Minneapolis looks as though it's surrounded by a ring of emptiness, but it isn't: It surrounded by a ring of neighborhoods with mixed political interests.
We can see the same effect on a bigger scale if we look at the region around St. Louis.
Or, to a lesser extent, the Gulf Coast.
Big cities with lots of blue fading into areas with blue and red voters that then become rural red zones.
It's not a new revelation that cities are blue and more rural areas are not, of course. It's just fascinating to look at places that we think of as red on our maps and see that it's a more complicated picture than that.
Salt Lake City:
No map is perfect. But these maps have the benefit of making clear what everyone knows intuitively: Most people live in urban regions and those regions, like the more accurate presidential result maps, tend to blend red and blue in more intricate ways than we generally realize. Particularly when we're looking at county-level data.
That said, there are still some urban areas where that's less of the case. Like the urban area where Trump now lives.