TLP's 2024 Swing-State Project: Pennsylvania (Part Two)
On PA demographic trends and voting patterns.
Over the previous decade, Pennsylvania experienced modest population growth (2.4 percent), with the largest gains concentrated in southeastern part of the state outside of Philadelphia. However, the county that experienced the greatest growth during that period was Cumberland, which is more centrally located—just west of the state capital of Harrisburg. The county netted 24,000 new residents between 2010 and 2020 thanks to the arrival of several e-commerce giants that brought new jobs to the area.
Pennsylvania is whiter than the nation as a whole, though the white population was the only racial demographic group in the state to experience a net decline during the past decade. The state’s black and Asian populations tend to be clustered near the major metropolitan areas. By contrast, Hispanic Pennsylvanians are likelier to live in the Lehigh Valley and Northeast Pennsylvania.
Like most other states, white voters in Pennsylvania are likelier to vote Republican while voters of color are likelier to vote Democratic—often by overwhelming margins. Still, the trajectory of each group’s vote patterns is just as important as the party they tend to back. For instance, though Trump won a majority of white Pennsylvanians in both 2016 and 2020, his advantage with them shrunk between those cycles. After Clinton won 39.3 percent of white voters, Biden captured 42.7 percent four years later. Though this change may seem trivial, whites made up over 82 percent of the electorate in both elections, so Biden’s gains were crucial to his win here—especially given that black, Hispanic, and Asian voters all swung more Republican relative to 2016.
Democrats have long had an advantage with younger age cohorts. However, Biden appears to have struggled significantly with these voters throughout his first term. After winning those aged 18–44 by wide margins in 2020, more recent polling has shown that these groups may have soured on him heading into his re-election bid. It remains unclear whether these voters will revert to typical voting patterns once the 2024 election rolls around or whether the poll results portend a meaningful shift in these generations’ voting behaviors. One thing is for sure, though: Biden appears to have a lot of work ahead of him to recoup these losses.
Union voters have historically been a core constituency for Democrats. Unfortunately, as in other states, union power in Pennsylvania has been diluted over the past several decades, significantly weakening their electoral impact. Not only do union households produce fewer votes than they used to, but the declining potency of workers’ rights as a voting issue has consequently led many working-class voters who hold more culturally conservative attitudes to shift toward Republicans.
Population and Demographic Characteristics
Following the 2020 census, Pennsylvania had 13 million residents, making it the fifth-largest state in the country. Compared to one decade prior, this constituted a 2.4 percent population increase—the eighth-slowest growth of any state. The largest concentrations of residents are around the state’s two biggest metro areas: Philadelphia and Pittsburgh. Collectively, Philadelphia, its four collar counties, and Allegheny County compose 42.1 percent of the statewide population. Another 12.8 percent of Pennsylvanians reside in four exurban Philly counties: Lancaster, Berks, Lehigh, and Northampton.
Fewer than half (23) of Pennsylvania’s 67 counties experienced net population growth over the previous decade, the bulk of which are clustered in the southeastern part of the state. Among the top-five fastest-growing counties, three—Chester (+7.1 percent), Montgomery (+7.1 percent), and Lehigh (+7.2 percent)—are located outside of Philly. In fact, not a single county covering Philly’s immediate suburbs or even the exurbs further out saw net population loss. On the other side of the state, Allegheny County and two adjacent counties—Butler and Washington—also saw modest gains.
The most interesting development may have been in Cumberland County, which grew far more than any other county. Situated just across the Susquehanna River from the state capital of Harrisburg (part of neighboring Dauphin County), Cumberland netted 24,000 new residents. Its growth has come as Amazon and other e-commerce companies with warehouses in the area have set up shop there. Although Cumberland is more racially homogeneous than the average Pennsylvania county, with a CVAP that is 88.5 percent white, nearly 40 percent of its growth came from non-white populations.
By contrast, much of the remainder of the state—heavily rural and exurban—saw substantial population loss. Fully 18 counties shed at least five percent of their population. It is worth noting, though, that some of these counties have disputed the census figures showing these losses, claiming that the pandemic made it difficult to reach many of their residents.
Overall, Pennsylvania is a fairly white state. According to the 2020 census, its CVAP was 80.8 percent non-Hispanic white, 10.1 percent black, 5.4 percent Hispanic, and 2.3 percent Asian. Like most states, though, it also grew more diverse over the past decade. The only racial sub-group with a net CVAP decline was whites (-61,195 residents), while the black (+88,800), Hispanic (+229,961), and Asian (+82,550) populations all ticked up. The counties with the largest shares of black residents are largely based around major population centers: Philadelphia, Pittsburgh, and Harrisburg. Meanwhile, counties with a higher share of Hispanic residents than the statewide average are mostly in the eastern half of the state—specifically, in the Lehigh Valley and Northeast Pennsylvania. And counties with higher-than-average shares of Asians residents are clustered heavily in the Philadelphia region as well as the Dauphin-Cumberland area and Centre County.
Voting Trends by Demographic Groups
For this section, we used a variety of sources. When analyzing voting trends broken down by race, sex, age, and education, we used data from the States of Change project. For the partisan ID, we used AP VoteCast survey data, which gauged vote choice by voters’ self-identified partisanship. Finally, we rely on the traditional exit poll to examine union households and show how their vote preference and share have changed over time.
Race, Education, and Sex
The racial composition of Pennsylvania’s electorate very closely matches that of the state’s CVAP: 82.3 percent white, 10.1 percent black, 4.4 percent Hispanic, and 3.2 percent Asian. As in most states, white voters in Pennsylvania are the only racial sub-group that leans Republican, breaking for Trump in 2020 by roughly 13 points. However, there is a massive split among these voters along education lines. In 2020, white voters with a college degree backed Biden by ten points while their non-college counterparts supported Trump by a massive 28.5-point margin. Both margins for Biden represented an improvement on Clinton’s 2016 performance.
Black voters saw the least change from 2016 to 2020 regardless of educational attainment, with both college-educated (R+0.4) and non-college (R+2.0) voters barely shifting. Among Hispanics, there was substantial movement. Hispanic degree-holders went from backing Clinton by 44.5 points to Biden by 38.4 points, a 6.1-point swing. Those without a degree, meanwhile, moved rightward by a massive 20.5 points, making them a less Democratic cohort in 2020 than their college-educated counterparts—reversing the dynamic from 2016. Finally, the performance of Asian degree-holders remained fairly static between the two cycles, but there was a large 14.6 point rightward shift among non-college Asians.
Biden’s ability to flip Pennsylvania from Trump in 2020 hinged significantly on making inroads with white voters. These gains appeared to come almost entirely from those who voted third-party in 2016, as Trump’s support among white Pennsylvanians remained virtually unchanged. Additionally, some of Biden’s largest gains among all demographic groups came from white non-college men, who voted nearly seven points more Democratic in 2020 than in 2016. Most impressively, he made these gains as turnout among the state’s white population grew, going from 64 percent in 2016 to 71.5 percent in 2020.
While Biden will need to work at retaining as much support from white Pennsylvanians as he can, these voters—especially those without a degree—still lean Republican by a healthy margin. This means he’ll also have to focus on regaining lost ground with many of the non-white voters that defected from him in 2020. Unfortunately, early signs indicate he has lost ground with these groups since the last election. An October 2023 New York Times/Siena poll found that black voters, who supported Biden by an overwhelming 93-point margin in 2020 (96 to 3), now only back him by 51 points (71 to 20). Among all other non-white voters, he only leads Trump by 22 points (55 to 33).1 This mirrors several national polls that have also shown Biden significantly underperforming his 2020 margins with these groups.
Vote preferences by age in Pennsylvania follow a similar pattern as other states: the youngest voters are the most Democratic-leaning, and voters grow more Republican by each successively older cohort. In 2020, voters aged 18–29 backed Biden by 26.7 points, up from their 23.6-point margin for Clinton. The next oldest group, those aged 30–44, were also the second-most Democratic-leaning and swung left relative to 2016 by the most, voting for Biden by 13.8 points after supporting Clinton by 7.2. The two oldest age brackets—45–64 and 65 and older—are the most Republican-leaning, make up the largest segments of the electorate by age, and have the highest turnout rates. In 2020, they voted for Trump by 8.9 points and 11.1 points, respectively.
Heading into 2024, Biden may face a serious problem: the two youngest age cohorts in the state appear to have soured on him immensely, which tracks with national trends in the latter part of the year. The October 2023 Times/Siena poll found that Pennsylvanians aged 18–29 now only support him in a theoretical rematch with Trump by 11 points, a rightward swing of 15.7 points from 2020. The erosion of support from the next-oldest age bracket was even starker: voters aged 30–44 went from supporting Biden in 2020 to now backing Trump by six points, constituting a nearly 20-point swing. This mirrors a December 2023 poll from Muhlenberg College, which found that Biden’s advantage with the state’s youngest cohort had fallen substantially since 2020. However, the Times poll also showed that Biden has gained ground with those in the two oldest brackets, who are more reliable voters.
To be sure, there can often be a lot of statistical noise around the performance of various demographic groups in state-level polls, and it’s entirely possible that Biden’s seeming trouble with younger voters is overstated. But these results mirror national trends as well, indicating he may indeed have a lot of work to do to rebound with Pennsylvania’s young people.
Mirroring voter-registration trends, most of the voting electorate identifies with one of the two major political parties. The AP VoteCast survey from 2020 showed that only five percent of voters that cycle considered themselves true independents. The rest of the electorate was evenly divided: 46 percent identified as Democrats or Democratic-leaning independents while 49 percent were Republicans or Republican-leaning independents.
That cycle, Biden did what he needed to among all three groups. First, he mostly kept Democrats in his column, winning them over Trump by 87 points. Second, he made modest but important inroads with Republicans, carrying nine percent and reducing Trump’s advantage with them to 81 points. Finally, the true independents broke decisively for Biden, 55 to 38, which likely helped him secure the win. Given his slim margin of victory statewide in 2020, Biden will need to either repeat this performance or make further inroads with one of these groups to offset losses elsewhere.
Union household voters in Pennsylvania have historically been a strong constituency for Democrats—from 2000 to 2014, the party’s candidates have averaged 61 percent support from them in top-of-the-ticket races, according to the exit polls. However, this dynamic appears to have changed considerably during the Trump era. While the exits did not ask about union affiliation in the 2016 presidential election, we know that white working-class voters across the state swung toward Trump. And as the 2020 results show, it’s not a stretch to think that Clinton’s support from union households hit a record low: Biden appeared to narrowly lose these voters to Trump in Pennsylvania, 49 to 51 percent, as he flipped the state back into Democrats’ column.2
However, the party’s struggles with union households are not just due to waning support but also the overall decline of unions in the state. In 2000, they composed nearly a third (30 percent) of the electorate. Over the next two decades, that number steadily fell until it reached just 18 percent in both the 2020 and 2022 elections. This has occurred in tandem with declining unionization rates in the state. During that same two-decade period, union membership dropped from 17 percent to 12.7 percent—not nearly as steep a drop as in some other Midwest states but an impactful shift nonetheless.
Overall, this decline in both union household vote share and support for Democrats since 2000 has made things more difficult for the party in Pennsylvania. We estimate that these trends have contributed to a loss of almost 350,000 Democratic votes between 2000 and 2020. Of course, the fact that Biden still won indicates he was able to make up for this severe drop-off in other areas, such as significantly outpacing Gore among college-educated voters.3 Still, even in the face of declining union support, these voters remain a crucial constituency for Democrats in Pennsylvania. Finding ways to stem these losses will be vital to staying competitive here in future elections.
[Part one of this report examining Pennsylvania political history, geographic trends, and voter turnout history is here.]
Michael Baharaeen is the director of political research at Blue Compass Strategies. He is a native of Kansas City and writes the Checks and Balances newsletter on Substack.
Appendix: Pennsylvania Media Markets Overview
Of course, we caution against reading too much into these figures one year out from Election Day. Moreover, we can only glean so much insight from two different sets of polls.
The AP VoteCast survey found that Biden did win these voters over Trump, but only by five points, 52 to 47, which still indicates lackluster support.