Analyzing the 2020 Election Results of Pennsylvania

Lab Reports, Maps


Presidential campaigns require many resources and investments, so campaigns need to be selective about which states and counties they want to invest into. Demographics also change over time, and I was interested in analyzing voting patterns from one of the swing states (and also my home state), Pennsylvania, by county. 

Questions of Interest:

  1. Which counties have a preference for a certain party, and what are the potential reasons behind it?
  2. How different are the political landscape and voting patterns compared to 2020 versus four years ago?



  • ArcGIS Online – for data collection and organization
  • ArcGIS – for data visualization

The data was found through ArcGIS, and visualized as an interactive web map in the same program.

Method and Process

Obtaining and Filtering the Data

In ArcGIS Online, I searched for potential feature layers to use for my topic. I started to search with phrases such as “presidential election 20XX”, and decided to add in a layer featuring the 2020 Election results for all states. Then, I added a filter expression in order to view just the state of Pennsylvania and its counties.

Stylizing the Data

First, I changed the base layer to a Dark Gray Canvas so that it is easier to see Red and Blue hues. I then selected a style that would be good for measuring multiple numeric fields. The style consists of blue and red glowing dots representing the Democratic and Republican parties, and the size and intensity of the dots represent the size of the population who voted for each county. Lastly, I added labels of the County names in a small, non-intrusive type style.

Additionally, I created a bar chart that shows the same data in a different format, and compares the parties further.

Following the visualizing of the 2020 results, I finally decided to compare the results from the 2016 election. In the updated map below, the results of the 2016 election by county is represented by a series of diamond shapes that are layered on top of the existing circles that represent 2020.


Based on the dot sizes, it appears that many of the urban areas (i.e Philadelphia) had a higher preference for the Democratic party, whereas the more suburban and rural areas leaned towards the Republican party. In other words, there is a visible difference in political party preference between those who live in more populated, urban parts and those who live in less populated, rural areas of Pennsylvania.

In comparing both the years 2020 and 2016 election results, the party preferences remained mostly similar. The only counties that seem to have shifted in party preference are Northampton and Erie (see visual below).


I feel that the map I created shows a solid summary of the election results – it compares population size and political parties simultaneously.

Overall, I have a good understanding of how to stylize a map on ArcGIS through the data provided by the program. Next, I hope to learn how to import my own datasheets and use them to create my final project via ArcGIS.