Feb 21, 2017

U.S. House, Indiana District 9 General Election 2010-2016 Visualization

This is my first attempt to create a choropleth map - a map that visualizes measurements by shading geographic regions. I used election results data from in.gov - general election of US House representatives from Indiana Congressional District 9, years 2010, 2012, 2014, and 2016. The maps below represent percent of people who voted for Democrat party Candidates (Baron P Hill in 2010, Shelli Yoder in 2012 and 2016, and William Bailey in 2014).

The process was tedious, but straightforward:

  • Find data and get it into appropriate format (some manual copying from PDF was needed)
  • Calculate statistics needed for mapping (here percent voting for Democrats within county)
  • Get geographic (shapefile) data
  • Combine stats and geographic data
  • Generate choropleth map

This tutorial on creating maps with R and this vignette about tmap package were very helpful.

A quick analysis of the District 9 US House elections over time shows that some counties (e.g., Monroe county) are strong in voting for Democrats and some counties (e.g., Morgan and Orange counties) are much weaker. In 2012 though Orange, Washington, Harrison and some other counties suddenly had nearly half of county voters voting for Democrats. The turnout in 2012 was higher than in 2010, but it was comparable to 2016, when Shelli Yoder was the candidate again. The year of 2012 was also when only two candidates ran, so may be we need to look at other candidates and how they take votes. More data and more analysis needed.