How Allegheny County delivered Pennsylvania to Biden

Crowds march across the 10th Street Bridge in celebration of Joe Biden’s victory on Nov. 7, 2020. (Photo by Nick Childers/PublicSource)
Crowds march across the 10th Street Bridge in celebration of Joe Biden’s victory over Donald Trump on Nov. 7, 2020. (Photo by Nick Childers/PublicSource)

While the national media has pointed to voters in Philadelphia or Pennsylvania’s small population centers, Allegheny County was crucial in putting Biden over the top.

By Oliver Morrison
Public Source

Nov 12, 2020 – oe Biden was declared the winner of the 2020 presidential election after the Associated Press and other outlets declared him the winner of Pennsylvania. Although the vote margins are close in Wisconsin, Arizona and Georgia, Pennsylvania was the state that tipped the scale enough to call the election.

So, how did he win Pennsylvania? The New York Times attributed Biden’s win to “counties east of the Appalachians [that] shifted left.” The Washington Post argued that “it wasn’t Pennsylvania’s major urban centers that set the result in 2020.” Instead, they wrote, “It was Erie County and other places like it, where relatively minor shifts across a wide swath of small, industrial cities, growing suburbs and sprawling exurbs.”

But if Allegheny County voted for Biden as predictably as it had for Democratic candidates the past five elections, the results this year could still be uncertain. It was Biden’s unusual, historic performance in Allegheny County, alongside one suburban Philadelphia county, Montgomery County, which provided enough of a margin for Biden to definitively win.

As of Wednesday evening, Allegheny County had already recorded the vast majority of its votes, more than 717,000, the largest number of ballots cast since more than 719,000 votes were cast when Lyndon Johnson was elected in 1964. And the 1964 election was near the peak of the county’s population boom when about 30% more people called Allegheny County home. There are still some provisional and overseas ballots that haven’t yet been included and just under 1,000 additional ballots that were postmarked by Election Day and arrived within three days.

PublicSource looked at how each of the 1,323 precincts in the county voted to tell the story of how Biden won. As the last ballots are counted, it could change the results in single precincts that are close. We’ll update this piece with any changes once all the votes are tabulated.

Five takeaways:

–Allegheny County was one of two counties in Pennsylvania, along with Montgomery County, where Democratic votes increased enough to give Biden a definitive win.


–Both presidential candidates increased the number of votes their party received compared to 2016.

–Biden is winning by nearly 146,000 votes, the biggest margin in Allegheny County since 1964. The urban core and most of the suburbs voted for Biden. Trump’s wins came largely on the edges of the county such as in Findlay, Fawn and Elizabeth townships.


–Some of the biggest gains for Biden from 2016 were in suburban and rural precincts, some of which he still lost. Some of Trump’s biggest improvements were in primarily Black neighborhoods in the urban core, as well as in patches of the Mon Valley. While Trump expanded to the urban core, Biden expanded almost everywhere else and ultimately won the county by the largest percentage since 1992.


–Allegheny County was one of the two most important counties for Biden


As of Wednesday night, Biden led Donald Trump by 51,301 votes in Pennsylvania, according to the state tally, enough votes to prevent an automatic recount and likely enough votes to survive any legal challenges that Trump attempts.

Allegheny County delivered around 47,000 more votes for Biden than the average Democratic presidential candidates since 2000. And he won more than 37,000 additional votes compared to Hillary Clinton in 2016. Only Montgomery County moved in Biden’s direction by about the same number of raw votes: he’s winning Montgomery by about 37,000 more votes than Clinton did according to the state tally. Allegheny and Montgomery Counties are the second and third largest counties in the state, less populous than Philadelphia.

Their additional votes make any recount or legal efforts unlikely to change the outcome. Although Biden increased his vote margin in other Pennsylvania counties — Allegheny and Montgomery Counties shifted definitively to secure his victory.

The last five presidential elections in Allegheny County have had predictable results. The Democratic candidate earned between 56-57% of the vote, the Republican 40-42%. The Democratic candidate won by between 90,000 and 108,000 votes. The average number of votes Democrats gained in those five elections was 98,236.

That predictability changed dramatically this year: Allegheny County has already delivered at least 145,815 more votes to Biden than to Trump.

If Biden had performed just as well as Clinton in Allegheny County — with all else being equal — he would be winning the race in Pennsylvania by fewer than 15,000 votes. That likely would have triggered an automatic recount and could have made Biden’s margin more susceptible to legal challenges.

Although Philadelphia voted more overwhelmingly for Biden — where he is winning by nearly 450,000 votes in total — Philadelphia’s support for Biden was actually lower than its support for Clinton, who won by more than 475,000 votes.

Based on data available so far, Biden appears to be receiving more votes from white suburban voters, while Trump is picking up a higher share of Black urban voters than last time.

Biden’s blue wave

Biden’s core support locally is still in Pittsburgh. Biden received more votes in 392 out of 402 precincts in the city. And with few exceptions, Biden’s support carried into the suburbs immediately outside the city, including Mt. Lebanon to the south, Fox Chapel to the north and most of Monroeville to the east. But the outer edges of the county, such as Elizabeth Township, Findlay Township and Fawn Township favored Trump.

[The data from all the maps in this story is from Wednesday morning when there were just over 700,000 votes tallied. As of Wednesday night at 10 p.m. around 10,000 ballots had not yet been added to the precinct totals. We will update the maps once all the votes are uploaded.]

Despite this, Biden also owes his victory in part to increases in support in many of these areas where he lost. Four out of the five precincts where Biden increased his vote total the most were in areas Trump won and where Trump also gained hundreds more votes compared to his performance in 2016. Biden kept pace or nearly kept pace with Trump’s increases in most rural areas.

While Biden’s core voters are disproportionately Black and live in Pittsburgh, he actually did worse than Clinton in many of Pittsburgh’s Black neighborhoods.

Only seven of the 20 precincts where Biden’s vote increased the most from Clinton’s were in Pittsburgh. The others were in places like North Versailles, North Fayette, Moon, Shaler and Monroeville. For example, in one precinct in Moon, Biden received 853 votes even though Clinton had only received 209.

Some of the changes were dramatic. In Haysville, only 16 voters picked Clinton but 402 chose Biden. In one McKeesport precinct only five voters picked Clinton in 2016 but 245 chose Biden.

Trump’s pickups came from rural Allegheny County and historically Black neighborhoods
Trump has received more than 20,000 additional votes in 2020 in Allegheny County compared to 2016. Some of these increases came from rural and suburban municipalities such as Elizabeth, Pine and Findlay, where he often doubled or tripled his 2016 vote totals. His increased support though was geographically broad: He received more votes in 2020 than 2016 in more than 54% of the county’s precincts.

But the results were not always consistent or easy to interpret. For example, Moon Township contained three of the 10 precincts that improved the most for Trump; it also contained two of the 10 precincts where Trump’s vote total fell the most. Moon District 13, just west of Robert Morris University, increased its support for Trump more than 200%. But about two-thirds of that increased support was canceled out by its neighbor, Moon District 9, just northeast of Pittsburgh International Airport, where Trump’s support fell from 729 to 241 votes.

Some of Trump’s biggest and most surprising increases in support came in historically Black neighborhoods and Pittsburgh’s urban core. In one precinct in West Homewood, which includes the predominantly Black Shiloh Community Baptist Church, Trump received only three votes in 2016. In 2020, he received 105 votes.

This happened in other historically Black Pittsburgh neighborhoods, such as the Uptown, Ward 1 District 2: Trump received 40 votes in 2016 but 416 votes in 2020. A few precincts away in the Hill District in a precinct that includes the neighborhood Carnegie Library, Trump increased his support, from one vote to 167 votes, the second largest percentage increase in the county.

In the Mon Valley municipalities of Braddock, Rankin and North Versailles, voters picked Trump in much larger numbers in 2020. A single precinct in North Versailles drew almost 1,000 additional votes toward Trump, his largest single vote increase across the county.

The race of individual voters, however, is not known, and some of this support could be coming from white voters who live in predominantly Black areas. For example, Braddock is about two-thirds Black and in one precinct Trump’s support increased from 12 votes to 122 votes. But in West Mifflin, which is about 87% white and located right across the Monongahela River, Trump’s support jumped even more: from 3 votes to 509 votes.

What changed from 2016 to 2020?


One of the most interesting results of the 2020 election is that Biden gained some of his biggest margins in Trump’s strongholds. And Trump made his biggest gains in Biden’s strongholds. But while Trump made inroads in Pittsburgh’s urban core, Biden made inroads almost everywhere else.

A good example is Richland Township. Trump won all eight precincts in 2016 and still won all eight this year. But Biden gained ground in seven the eight precincts and ultimately picked up 287 additional votes there compared to Clinton in 2016.

That same story was true in other more rural areas of the county that Trump still won, such as Pine, Findlay and Jefferson Hills. Biden not only gained ground but earned enough support to win some of the outlying suburbs that Clinton lost, such as McCandless, Ross, White Oak and Upper St. Clair.

Oliver Morrison is PublicSource’s environment and health reporter. He can be reached at oliver@publicsource.org or on Twitter @ORMorrison. This story was fact-checked by Matt Maielli.

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