The Pennsylvania Republican Party has experienced a surge in membership over the past year.

This phenomenon has been used as evidence that Donald Trump is resonating in the Keystone State. This weekend, Politico Magazine published yet another study of a traditionally Democratic town that is anxious for The Donald to “Make America Great Again”.

All the while, Trump has been close to Clinton in PA polls recently.

After digging into the voter registration numbers, it is entirely possible that Trump could win Pennsylvania’s twenty electoral votes come November. The idea that he is single-handedly changing PA’s electorate, though, has little support.

As I’ve written ad nauseam, the famous apocryphal comment that Pennsylvania is Pittsburgh, Philadelphia and Alabama in the middle is no longer accurate (if it ever was).

Instead, Pennsylvania is a tale of two states. The western half is rural. It was home to countless Steel plants and union Democrats. The eastern half is suburban, college-educated and was once a hotbed of Rockefeller Republicans.

The Western half, Appalachia, has become increasingly conservative. More Midwestern than Northeastern, residents are fervently anti-trade as they see it as the cause of the downfall of the industry that once employed them.

The eastern half, Acela, began turning Democratic in the 1990’s. It’s closer to New York than the middle of the state, both literally and figuratively. The cosmopolitan and economically prosperous Southeast is the pivotal swing portion of the commonwealth.

Despite all this, though, the Southwest still contains a great deal of registered Democrats. West Virginia and eastern Kentucky also contain a large number of Democrats who feel betrayed by the party.

The reason is as much historical and it is cultural. From the 1964 Civil Rights Act to the 1994 Gingrich Revolution, the South transitioned from the Democratic Party to the Republican Party. The upper Appalachian areas were the last to change.

There could be many culprits for this but my best guess would be the United Mine Workers union and its influence in this coal-heavy region. Eventually, though, that business began to die out and the UMW went from backing Walter Mondale and Michael Dukakis to refusing to endorse Barack Obama in 2012.

For example, there are nine Southwestern counties where Dems still have a voter registration edge.

Pres. Obama won one, Allegheny home to Pittsburgh, four years ago.

Dave Wasserman of FiveThirtyEight has charted the degree to which the region has flocked to Republicans since 2008.

So if Trump is really changing the Pennsylvania electorate, the voter registration shift should be taking place in large numbers outside of the Southwest.

That hasn’t really been the case. From May 2015 to April 2016, the gap between registered Dems and registered Republicans narrowed by 63,406.

About half of those gains, 30,860, came from the nine Southwestern counties.

To put that in perspective, let’s look at the SEPA counties where Dems hold a registration advantage (Bucks, Delaware, Montgomery and, of course, Philadelphia). Altogether the Democrats increased their lead by 29,482 voters in that region, nearly canceling out the GOP’s gains in the Southwest. On top of that, if you include Chester County the Dems added 31,360.

In fact, Chester was the only county where Republicans hold a registration advantage yet Democrats gained ground over the last year. A mere six counties total are bluer now than a year ago, with only Centre (State College) and Dauphin (Harrisburg) being outside the Southeast.

One underrated area of concern for Democrats, though, is the Northeast and Lehigh Valley. Seven of those counties have a Dem voter registration edge and Obama won five of them in 2012, yet Republicans gained 19,943 members in that area. Although a substantial amount of them came from Luzerne County, home of Wilkes-Barre, so it may be a case of one city changing rather than the whole region.

Overall, there’s little evidence to suggest that Donald Trump is altering the Keystone State, but that doesn’t mean that the commonwealth isn’t changing.