The political geography of Sangamon County

Maps fascinate me. They’re not only useful for navigating physically, but also mentally. I think studying (and producing) maps enhances a person’s sense of direction, spatial reasoning and appreciation of scale. In practical terms, maps can help you make sense of things.

To illustrate the 2014 election results in my county (Sangamon County, Illinois), I made a series of maps depicting party predisposition by precinct. (Alliteration!) It took a lot of work, and it would not have been possible without the awesome work of the folks in the GIS department at the Sangamon County Clerk’s office. They produced the shape files that define the precincts, which allowed me to assign the data to physical areas. For this project, I learned how to build a web scraper with Outwit Hub, which collects data from websites and compiles it into a handy table.

The map below depicts which way each precinct leans politically. To do this, I collected all of the election results by precinct in the races for governor, U.S. Senate, 18th Congressional District, 13th Congressional District, 48th Illinois Senate District, 96th Illinois House District and Sangamon County Sheriff. Next, I averaged the percentage for all Republican candidates and all Democrat candidates in each precinct. That allowed me to see which precincts voted more for Republicans than for Democrats and vice versa. The map illustrates that all precincts outside the City of Springfield leaned Republican, while several within the city leaned Democratic. An interactive version of the map is here:

red blue

While that map shows a concentration of Democratic support in the northeast quadrant of Springfield (which I reported on here), there is no sense of degree here. Looking at that map alone might lead the viewer to conclude that all the red precincts supported Republicans in equal measure.

To get a more nuanced view of party support, I made two additional maps. The first shows the percentage of Democratic support in each precinct. The strongly blue areas have the highest Democratic support, while the lighter areas have less.


The second map shows the opposite, depicting Republican support. These maps allow the viewer to see the support for each party even in heavily partisan precincts.


To view the interactive version of the Democratic support map, visit For the Republican support map, visit

As I reported in my article, the most interesting part of the elections wasn’t who won; it was that even heavily Republican precincts voted in favor of ballot questions that Democrats hold dear and Republican politicians often rail against. Case in point: raising the minimum wage, which passed in even the least supportive Republican precinct by 56 percent.

Why did that happen? One of my sources put it more charitably than I would have:

Asked why Republicans might support issues that are usually Democratic platforms, Turner said simply, “I believe these are all quality of life issues that cut across party lines.”


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s