Inspired by the recent state elections in PA, I spent a while today staring at the county results for PA in the 2012 and 2016 elections. I figured I might as well use this old thread to continue discussion on PA. Here's my take on the state in 2016:
I roughly divided the counties into three groups: major metro areas (Philly, Pittsburgh, and Pike County, which is part of the NYC metro area and is so small that it doesn't really affect results anyway), the remaining metro areas (as defined by the US Census), and all other counties.
Major metro areas (~1/2 of total vote):
Summary: Compared to 2012, Democrats actually did pretty ok here due to gains in Philly suburbs
2012: Obama 59-Romney 40
2016: Clinton 58-Trump 39
Between 2012 and 2016, Democrats made significant gains in just three PA counties: Allegheny, Chester, Montgomery; Allegheny contains the city of Pittsburgh, while the latter two counties are in the Philly metro area. One other thing that stands out about all three counties is that they're the only counties in the state where Trump received significantly fewer votes than Romney had (he also finished slightly behind Romney in Delaware County); it seems pretty likely that Romney-Clinton voters were important here. Democrats lost a fair amount of ground in the city of Philadelphia, but ultimately it wasn't that big of a deal compared to other shifts in the state, and Democrats still won by a margin of 475k votes in the city (compared to 490k for Obama). Bucks and Delco, the other two counties in SEPA, didn't see a major movement towards either party. Overall, Democrats actually improved on their performance in the Philly metro area by just under 50k votes.
The gains in Allegheny (which has about 4x the population of the city of Pittsburgh) were overwhelmed by significant losses in every other county of the Pittsburgh metro area; Obama won 40% in three of the non-Allegheny counties in the Pittsburgh metro area, while Clinton didn't win 40% in any of them. The most important of these counties, Westmoreland, went from 38% Obama to 33% Clinton. The Republican margin in the Greater Pittsburgh area increased from 14k votes in 2012 to 58k votes in 2016, the third-largest gain either party made in any single metro area (after Scranton-Wilks-Barre and Greater Philadelphia).
Despite overall losses in the Pittsburgh metro area and a decline in the city of Philadelphia, the gains in Allegheny, Chester, and Montco left the Democratic margin in the metro areas unchanged: they won them by about 600,000 votes in both 2016 and 2012. With that said, one could make the argument that Democrats
should have made more gains here, especially in Philadelphia. And while every county in the major metro areas saw an increase in
turnout, so too did every other county in the state, and as a share of Pennsylvania's vote the major metro areas declined from about 54% in 2012 to about 53% in 2016.
Other metro areas (~1/3 of total vote):
Summary: Democrats held their own ground in a few metro areas, but Republicans made major gains overall
2012: Romney 52-Obama 47
2016: Trump 55-Clinton 40
I'm going to divide these into four categories:
Places Democrats largely held ground: Democrats actually gained ground in Centre County (home to Penn State). Clinton also did pretty ok in two of the three metro areas of South Central PA (the exception being the the York-Hanover MSA), as she nearly matched Obama's 40% in Lancaster County, and the Dem share declined from 45% to 43% in the Harrisburg-Carlisle MSA. Overall, the Republican margin increased by about 10k here compared to 2012.
Moderate Republican gains: The Dem share fell from 52% to 47% in the Allentown-Bethlehem MSA (aka the Lehigh Valley), from 49% to 43% in Berks County, and from 39% to 33% in the York-Hanover MSA. The Republican margin increased by about 60k votes here.
Major Republicans gains: Obama won over 55% of the vote in both the Erie MSA and the Scranton-Wilks-Barre MSA, and Clinton declined by at least 10% in both MSAs. She also declined by 12% in Mercer County, a part of the Youngstown, OH MSA that Obama had nearly tied Romney in. Of all the PA metro areas, Scranton-Wilks-Barre saw the largest losses by any party between 2012 and 2016; Democrats went from winning it by 30k votes in 2012 to losing it by a little less than 30k votes in 2016. Overall, the Republican margin increased by about 90k votes in this category.
Smaller MSAs: Obama won 40% or less in the Johnstown MSA, the Altoona MSA, the Lebanon MSA, and the Williamsport MSA, and Clinton did significantly worse in all four. Each MSA cast less than 100k votes in 2012, but collectively the Republican margin from this category increased by about 30k votes.
One thing I noticed is that the total number of Republican voters increased in each county, while, with a few minor exceptions, all of the counties saw a decline in the total number of Democratic voters. Overall, the Republican margin of victory in these counties increased from about 100k votes in 2012 to about 300k votes in 2016. So Democrats won the metro areas (major and otherwise) by about 500k votes in 2012, but by just 300k votes in 2016.
Rest of state (~1/6 of total vote):
Summary: Democrats went from bad to worse
2012: Romney 61-Obama 37
2016: Trump 68-Clinton 28
These counties pretty much all tell the same story: Democrats went from bad to worse. The one exception is Monroe County, which went from a 56-43 Obama victory to a 49-48 Clinton victory. However, Monroe is in the eastern part of the state and is surrounded by MSAs, and (even from my own personal experience) it really seems to fit better in the "other metros" group. At least in this exercise, its voting behavior looks a lot like the neighboring Allentown-Bethlehem MSA.
Obama won between 40% and 45% of the vote in Columbia, Schuylkill, Clinton, Elk, Greene, Lawrence, and Warren counties. Not coincidentally, all of these counties are part of micropolitan statistical areas, meaning that they have a core urban area of at least 10k but less than 50k. Clinton's share of the vote declined by at least ten percent in every single one of these counties. Schuylkill, one of the three most populous counties in the non-metro group, stands out as the worst of these counties for Democrats; Obama won 43%, while Clinton won just 27%. Overall, the Republican margin in these counties increased by about 50k votes compared to 2012.
Obama won less than 30% of the vote in Juniata, Mifflin, Bedford, Fulton, Jefferson, Potter, and Somerset. Clinton declined by at least 5% in each one. Fulton was Obama's worst county (he won 21%) and Hillary's worst county (she won 13%). Even though all these counties are quite small, the Republican margin increased by 20k votes.
In all but one of the 21 remaining counties, where Obama won between 30% and 40% of the vote, Clinton's share of the vote declined by at least 5%. The one exception was Union County, where Trump actually won a smaller share of the vote than Romney did. This seems odd, especially since the biggest Democratic decline in this category happened in neighboring Northumberland County; the one thing that does stand out about Union County is that it's home to Bucknell University, a small but fairly prestigious liberal arts school. Anyway the total Republican margin in these counties increased by 85k votes.
Much like the mid-sized metros, every single county saw an increase in the total Republican vote, and all but one county (the mysterious Union County) saw a decline in the Democratic vote. So, even though Republicans were already winning all but one of these counties by fairly large margins, and proportion of the vote cast by these counties did not increase dramatically, Republicans went from winning these counties by ~200k votes to winning them by ~350k votes. Add up the 600k Democratic margin in major metro areas, the 300k Republican margin in other metro areas, and the 350k Republican margin in rural areas, and you get a 50k Republican victory (the exact Republican margin was 44,292 votes).
TLDR: Democrats lost ground in the city of Philadelphia, but more than made up for those relatively minor losses with gains in Chester County and Bucks County. However, they lost a significant amount of ground in most other metro areas, most dramatically in the Scranton-Wilks-Barre area and Greater Pittsburgh. Those losses, combined with Trump running up the score in non-metropolitan area counties, led to a Trump victory.
