Gov. Tom Wolf’s first term win in 2014 was the Democratic Party’s lone bright spot that year, representing its sole gubernatorial pick-up.

Just four years later, though, his re-election was mostly lost amidst a blue wave that featured the gain of seven governorships.

While both of his victories were substantial, they differed in a number of important ways. For instance, in 2018, Wolf lost eight counties he won the first time around, while only picking up one in return. Yet by gaining ground in the right places, Wolf increased his share of the vote from 54.93 percent to 57.77 percent.

Mapping out how he did so reveals plenty about both the commonwealth and his political coalition.

Philadelphia and southeastern Pennsylvania

First up, 2014:

And 2018:

The maps above show just how much more there is to learn from precinct-level maps as opposed to county ones. Sure Wolf carried all four of Philly’s collar counties twice, but it is in the margins where the real story lies. Despite running about three-quarters of a point behind his 2014 pace in Philadelphia, Wolf dramatically improved his margins in the surrounding area.

Counties he narrowly carried before like Bucks (52.33 percent) and Chester (51.80 percent) went for him with 58.54 percent and 61.33 percent of the vote, respectively, the second time around.

At the same time, dark blue counties like Delaware (60.91 percent to 66.71 percent) and Montgomery (59.86 percent to 67.18 percent) saw large margin jumps as well. Wolf accomplished this by winning both white-collar and blue-collar areas in these counties, a feat national Democrats must envy.

South Central Pennsylvania

2014:

2018:

South Central Pennsylvania has quietly been one of the brightest success stories lately for the state Democratic Party. The above images perfectly capture why, as small, deep blue city islands grow outward at a rapid rate into red seas. 

Cumberland County was Wolf’s big pick-up, thanks to the Harrisburg exurbs across the Susquehanna River. Over in Dauphin, the governor ran up the score in the capital and extended his dominance east to the point that he was able to carry Hershey.

All the while, Lancaster continues to trend blue as Wolf jumped up six and a half points (40.91 percent to 47.49 percent) in just four years. And though Republican Scott Wagner beat Wolf in the battle for their native York, Wagner couldn’t match Tom Corbett’s 2014 performance in the county.

Northeastern Pennsylvania

2014:

2018:

The Scranton/Wilkes-Barre corridor was in many ways responsible for Donald Trump’s victory in the Keystone State. In 2012, Barack Obama won Lackawanna County by 26,753 votes and Luzerne County by 5,982. In 2016, Hillary Clinton’s margin in Lackawanna was only 3,599 while she lost Luzerne by 26,237. Remember Trump took the commonwealth with a bare 44,292 vote advantage.

There was little indication of this sudden shift two years prior when Wolf breezed past Corbett. So while Wagner made some inroads compared to 2014, the governor largely held his ground in this crucial territory.

For example, Wolf’s margin in Lackawanna actually rose from 23,599 to 25,621, while it fell from 9,004 to 5,033 in Luzerne.

Lehigh Valley

2014:

2018:

The Lehigh Valley represents one of Wagner’s strongest areas of growth over Corbett, as he was able to pick off both Carbon and Schuylkill counties.

Yet at the same time, Wolf improved in Lehigh and Northampton counties to the point that he assembled a solid line of support through the neighboring counties, built on the cities of Allentown, Bethlehem, and Easton. Generally speaking, the closer any Democrat can get the Lehigh Valley to look like southeastern Pennsylvania the better for him or her.

State College/Central

2014:

2018:

Five years ago, the furor of Penn State alumni against Corbett was cited as a contributing factor to his defeat. At the time, I was skeptical of that opinion. Hindsight suggests that while the cumulative effect may’ve been small, Wolf did benefit in the State College area in 2014 only to fall back down to Earth during his battle for a second-term.

As a result, this area includes two of the eight counties that Wolf won in 2014 but lost to Wagner in 2018: Clinton and Northumberland.

Allegheny County/Southwest

2014:

2018:

Southwestern Pennsylvania has been hemorrhaging Democrats for decades, although Wolf seemed able to stem the tide four years ago. This phenomenon didn’t last as Cambria, Fayette, Greene, and Lawrence Counties all converted back to the GOP.

There were some silver linings in SWPA for Wolf, however, as he improved his performance in Allegheny, Beaver, and even Westmoreland (albeit he still lost that last one). Perhaps former Braddock Mayor John Fetterman had a hand in this development.

What Did We Learn?

1. The Acela/Appalachia Divide Continues to Grow

The Acela/Appalachia divide has been my pet theory for a while now and hopefully it’s plainly evident why. The ancestral Democrats in the Southwest are nearly gone. After all, their nominee scored just one county in the area outside Allegheny despite a 17-point statewide landslide.

Meanwhile, Wolf ran up the score in the heavily populated southeast and made further inroads into the south-central area of the commonwealth. In the not too distant future, the blue oasis that was once limited to Philadelphia, then spread to its collar counties, may meet up with Allentown in the north and extend fully from the Delaware to the Susquehanna. Democratic dominance in this region may very well come to rival the GOP hegemony outside of it.

2. Pennsylvania is Still An Uphill Battle for the GOP

Of course, there remains encouraging signs for the Republican Party in the Keystone State. The aforementioned gains in the southwest chief among them. There’s also indicators that the northeast is steadily becoming redder as Carbon and Schuylkill counties embrace them and Donald Trump eats into the old reliably blue Scranton/Wilkes-Barre corridor.

Nevertheless, the results in the southeast are a blinking-red warning sign. I’d go as far as to guarantee that if the 2020 Democratic presidential nominee hits Wolf’s margins in Bucks, Chester, Delaware, and Montgomery then they’ll win the White House. In fact, even getting within three points ought to do it.

Given the Democratic gains in the southeast and Allegheny County, as well as their ability to stem the tide in places like Scranton and Erie, Trump’s 2016 victory looks like more of a one-off than a portent of the future.

3. We May Be Underrating Tom Wolf’s Political Prowess

It would be easy to dismiss Wolf’s two victories as the result of a pair of poor opponents: a deeply unpopular incumbent (Tom Corbett) and a self-combusting challenger (Scott Wagner).

That is one way to view these two contests. Through another lens, though, Wolf beat a GOP incumbent during a Republican wave. And then after Trump pried away the state in 2016, cruised against an opponent running on a Trump-like platform.

So why does this matter?

Because as we’re already scouting out the potentially huge Democratic field gearing up to take on U.S. Sen. Pat Toomey, R-Pa. in 2022, it’s worth asking why Wolf is usually not included among them.

Sure he’ll be 74 in 2022. But the U.S. Senate isn’t exactly a haven of millennials. Toomey was saved in 2016 thanks to crossover voters in Philly’s collar counties. Wolf’s strength there should legitimately frighten Pennsylvania’s junior senator.

Then there’s one final possibility.

You don’t hear it mentioned much, perhaps because of the governor’s quiet personality and relatively low profile. Yet when surveying his electoral victories and the pivotal role Pennsylvania plays in national politics, it’s worth asking: Would Tom Wolf make a strong vice-presidential nominee in 2020?

Of course with such a crowded field developing, there’s sure to be plenty of contenders for the No. 2 spot with higher profiles. (It’s also worth noting that Wolf has repeatedly said he’s not interested in higher office.)

Nonetheless, there are several potential nominees — U.S. Sen. Kamala Harris, of California, comes to mind — who could see Wolf as the perfect person to balance their ticket.

A soft-spoken, scandal-free, two-term governor from an Obama/Trump state with 20 crucial electoral votes would be worth at least a lengthy look. While the odds are against such an outcome, we should be well aware by now that the unlikely can become reality in an instant.

Nick Field, of Bucks County, is the former managing editor of PoliticsPA. His published work has appeared, among other places, on PennLive and WHYY-FM.