As pundits ponder the reasons and implications of the voting behaviors in the 2024 election, I thought I’d start posting some real information in context of my own little slice of the world – Allegheny County, PA. With a population of over 1 million people and a very diverse economy, I thought it might make for some interesting reading.
I want to make a special note of consideration here: there are several precincts in 2024 that did not exist in 2020. This is natural. As we update census information, districts get redrawn to relatively congruent numbers with the lowest possible variation between them. For example, in a ward with 1,200 people we draw boundaries so that two precincts in a district doesn’t have 500 voters while another has only 200. To make it more congruent, those boundaries would be as closely drawn as geographically possible with 400 people per precinct. On my maps, these precincts changes are typically shown in white (no data) because there is no data for these areas in 2020. These precincts are sometimes shown as the extreme legend colors (darker colors) in comparison maps because of the absolute value change that occurs between a new district that is compared to one that didn’t exist in 2020. For example, Jefferson Hills 9 did not exist in 2020. That doesn’t mean Jefferson Hills got some new land mass and they created a district from new residents. It means the previously existing 8 districts were refactored and redrawn. Jefferson Hills registration in 2020 was 8,777 across 8 districts. In 2024, it’s 9,123 across 9 districts. The municipality’s districts were redrawn to accommodate that overall shift. Voter data limitations do not allow us to get more granular than precincts, so we cannot track individual voter or even block-to-block movements with the current county election results data. Again, these district changes were few and are called out in comparisons below where they are relevant to understanding the context of the specific map.
Maps displayed here are vector SVGs, which means they are high resolution and border boundaries will not pixelate as you scale, maintaining the integrity of the image. You can right click and download or share any of these maps freely. I’ve included buttons for SVG and PNG images for those who may not be able to open the larger SVGs.
As I relate more points of data, I’ll add more maps and post on my social feeds when I’ve got a new one posted. In the meantime, If you’ve got a data point you’d like to see plotted against one of more of Allegheny County’s 1,300+ precincts, drop me a note on social media and I’ll see what I can do.
Here are the data points I’m currently exploring:
As I relate more points of data, I’ll add more maps and post on my social feeds when I’ve got a new one posted. In the meantime, If you’ve got a data point you’d like to see plotted against one of more of Allegheny County’s 1,300+ precincts, drop me a note on social media and I’ll see what I can do.
Here are the data points I’m currently exploring:
2020 Biden-Trump Vote Margin
In 2020, Joe Biden beat Donald Trump in Allegheny County by a margin of 147,846 votes winning a total of 1,021 precincts. The total vote count for these two candidates in 2020 was 713,672.
A blue precinct here means a higher winning vote margin for Biden. A red precinct here means Biden lost the precinct. Darker values are higher numbers. Dark blue means Biden won by more, while darker red means Trump won by more.
Precincts won by the Democrat are concentrated in the urban core and spread out through many of the suburbs. Precincts on the county rim overwhelmingly voted Republican.
2024 Harris-Trump Vote Margin
In 2024, Kamala Haris beat Donald Trump in Allegheny County by a margin of 139,759 votes winning a total of 1,028 precincts, 7 more than Biden won in 2020. The total vote count for these two candidates in 2024 was 698,343 which was 17,329 fewer votes overall than in 2020.
A blue precinct here means a higher winning vote margin for Harris. A red precinct here means Harris lost the precinct. Darker values are higher numbers. Dark blue means Harris won by more, while darker red means Trump won by more.
Again, precincts won by the Democrat are concentrated in the urban core and immediate suburbs but the margin of victory in those precincts were smaller than in 2020. Precincts on the county rim again overwhelmingly voted Republican, many with higher margins than in 2020.
2020-2024 Registered Voter Change
This image shows the change in voter registration from 2020 to 2024. Overall, voter registration grew by 9,688 over the past 4 years. 602 precincts added registered voters and by an average of 4.49% per precinct and 703 precincts lost registered voters and by an average of -6.34% per precinct.
I used non-partisan colors here where Orange shows a reduction in registered voters and Green shows an Increase in voters registered. There are a few district changes between 2020 and 2024 as noted in the beginning of this post, specifically in Moon and Jefferson Hills, where new districts were created to account for changing population in those areas. The extreme coloring in these areas is a misnomer as districts in 2024 that did not exist in 2020 will show absolute values that cannot be compared to earlier districts. Again, the county had only a handful of these changes. Registration in Pittsburgh Wards 1, 2, and 6 seemed to increase significantly (by 500+ voters). Upper St Clair, Rankin, O’Hara and several Pittsburgh city precincts also seem to have significant reductions in registered voters. These areas need more study to determine if district lines changed in the past 4 years and, if so, how much movement occurred between them.
2020-2024 Dem Total Votes Change
This image shows the difference in voting for the Democratic candidate from 2020 to 2024. Red here means the Democratic candidate in 2024 underperformed the Democratic candidate in 2020. Harris underperformed Biden in 884 of 1,327 (67%) precincts in Allegheny County with an average underperformance of 28 votes per precinct. Overall, Harris underperformed Biden in Allegheny County by 11,708 votes.
2020-2024 Rep Total Votes Change
This image shows the difference in voting for Trump from 2020 to 2024. Deeper red here means Trump vote increased in 2024. Trump over performed in 503 precincts (38%) with an average improvement of 21 votes and underperformed in 774 precincts (58%) with an average undervote of -19 votes. Overall, Trump underperformed his 2020 vote in Allegheny County by 3,621 votes.
Summary
Here’s a quick table with a summary of votes by precincts won or lost by each candidate in 2024 vs 2020 with a few interesting observations:
- The number of precincts won by the Democratic candidate in 2024 was nearly the same as it was in 2020 (1,319 vs 1,321).
- Votes for the Democratic candidate were 11,708 fewer in 2024 while the votes for the Republican candidate were only 3,621 fewer.
- Voter registration increased by 9,688, but total votes cast for President across the country dropped by 17,329.
What are your observations of the voting data? Of if you just have an anecdote you want to share, that’s cool too! Let us know what you think on social media and if you tag us (@campaignplanners) we’ll respond.
If you’d like to see voting precincts in Allegheny County lined up against other data, let us know that too and we’ll create another map!
