Wednesday, November 08, 2017

US Election Results

The New York Times has mapped out the results of yesterday's elections in Virginia, New York and New Jersey. For these election results the newspaper has used the Mapbox GL mapping platform and provided users with a variety of different visualizations of each result.

The default view on the mapped results provides a simple choropleth view of the results in each county. This default view of the vote share allows readers to see the vote share of each candidate in each electoral precinct.

This 'vote share' view suffers from a common problem of electoral mapping, where larger rural precincts with less voters dominate the map at the expense of smaller urban precincts (where a majority of voters actually live). You can see in the screenshot above that in this 'vote share' view, for Virginia, the Republican Ed Gillespie actually appears to have won in most of Virginia, despite having lost the election.

To overcome this slightly misleading picture the NYT's electoral map also includes a 'vote density' view. In this mapped view the hue of the color used in each precinct is based on the density of voters. As you can see in the map above this helps to address some of the problems with the 'vote share' view. The muted red no longer visually dominates over the stronger hued blue on the map.

A third 'vote lead' view uses scaled circular markers in each precinct. The size of these markers reflects the size of the lead of the winning candidate in each precinct. Again this map presents a more accurate picture of the actual result of the election. Another 'shift from 2016' view uses colored arrows to show the swing in votes in each precinct since the last election. This view provides a great visual picture of the huge swing in Virginia from the Republicans to the Democrats.

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