A relatively quiet off-year election in Philadelphia last month had some good signs for Democrats in 2020.

Almost half of the city voters who cast general election ballots this year did not vote in the same election cycle four years earlier, according to an Inquirer analysis of voter data from the Philadelphia City Commissioners Office.

The data show that the city’s electorate is growing and that people who didn’t vote in the past are beginning to do so. In an overwhelmingly Democratic city, that suggests an energized Democratic electorate — one that could prove critical to the party’s hopes of beating President Donald Trump in Pennsylvania in 2020.

“This movement in Philadelphia County could tip the results of the 2020 elections,” said Mark Nevins, a Democratic strategist in the city. “You can draw a line from the growth in turnout and performance among Democrats in Philadelphia County to a Democratic win in 2020 in the general election, and it’s not that difficult to see that path.”

Municipal general elections are sleepy affairs in Philadelphia, with voters often showing up just for the primary, which often crowns the ultimate winner. But last month, about 47,000 more voters cast ballots than in November 2015, an increase of more than 18%. Many were new to municipal elections. About 7% to 8% of them sat out the 2016 presidential election even though they were registered to vote. Some of the turnout was likely driven by the historic third-party City Council campaign by Working Families Party candidate Kendra Brooks.

And while off-year elections and presidential elections are different beasts, the spike in turnout, following record numbers in the 2018 midterm elections, points to Democrats mobilized by Trump’s 2016 win. Trump won Pennsylvania by about 44,000 votes, a surprise victory that came in part because Philadelphia delivered fewer votes for Hillary Clinton than Democrats had hoped.

“There has been a pretty consistent story line since Donald Trump’s election, which is Southeastern Pennsylvania being agitated, voting in higher numbers than it normally does, and becoming more Democratic,” said J.J. Balaban, a Philadelphia-based Democratic strategist and ad maker.

Winning Pennsylvania again is a key part of Trump’s 2020 Electoral College strategy.

“An increase in energy and turnout in Philadelphia can make a big difference statewide given the size of Philadelphia, particularly given the very tight margin by which Donald Trump carried the state,” Balaban said.

Roughly speaking, this year’s general election voters broke down into three groups:

  • About 51% of people who voted in 2019 also voted in 2015, and many of these are older “super-voters” who cast ballots regularly. More than two-thirds of them also voted in the very low-turnout 2017 general election, and almost all voted in 2016.

  • About 36% were registered in 2015 but didn’t vote then. These voters tend to vote primarily in presidential elections, and most voted in 2016 but not in 2017.

  • The remaining 12.5% of voters this year registered after 2015. Many of these are young voters ineligible to vote four years ago. This category also includes people who recently moved to the city or hadn’t registered before.

Voter rolls are by nature messy and ever-changing, and some information is inaccurate or imprecise. But the data provide a rough view of voting habits by showing every registered voter’s history. By analyzing the histories of 2019 voters — those histories show when people voted, not whom they voted for — a portrait emerges of a newly engaged electorate that did not previously participate in municipal elections.

The newly registered voters

People are constantly registering to vote, especially young people who register soon after becoming eligible and people who register after moving.

That group of about 38,000 voters who cast a ballot this year and registered in the last four years is particularly concentrated around the city’s colleges and universities, as well as areas where people move a lot, such as Center City, the river wards, and portions of South Philadelphia.

The median age of this group was 31 at the time of the 2019 election, much younger than the overall median of 44.

The faithful super-voters

Then there are the super-voters, the group that votes in election after election.

These are the about 158,000 voters who cast ballots in both 2015 and 2019, and they form the reliable backbone for the city’s electorate. They’re older — the median age was 61 — and they tend to live in high-turnout neighborhoods that see less turnover.

More than two-thirds of them also voted in the 2017 municipal election, which had low turnout and was focused on the district attorney and city controller races.

Almost all of them, 98%, also voted for president in 2016.

The newly energized

The 109,500 voters who could be identified as being registered in 2015 but not voting that year are the big difference between 2015 and 2019.

These voters make up more than one in three of this year’s voters, and they appear to be newly engaged. They’re somewhere between the other two groups, neither new to the game nor habitual participants.

Their median age was 45, and they tend to live in similar areas to the super-voters, making them a potentially powerful political force if they can be persuaded to cast ballots. Many of them are “cicada voters” who vote only occasionally, and most of them also did not vote in 2017. And more than one in seven of these voters also didn’t vote in the 2016 presidential election.

For many of them, 2019 was the first time they voted in a municipal election.