If you follow the nominal votes in PA, it would seem it's trended Democratic over the last 20 years.
It's position relative to the nation as a whole is important. That trend is pretty bloody consistent - it's been reliably more Democratic than the nation as a whole, even when the GOP won it. Long story short if the Democrat wins the national popular vote, they're almost certainly winning PA and they'd likely lost the PV by a decent margin to lose PA. Yes, 2012 was a weird outcome but that doesn't make a trend, yet.