We need to be careful about reading too much into this. Democrats did very, very well in the 2018 midterms in this state, but they also had popular Democratic incumbents and very weak Republican challengers. A few years down the road, I see this year being an exception to Pennsylvania's purple status.
Wasnt just that, we have the congressional vote as well, and a similar overpreformance was seen there as well, not to mention state legislature races.
Yeah but there's a top-down effect generally. This can be seen in cases like Kansas and Oklahoma, with D's doing very well in OK-05, KS-03, and KS-02 with overperforming Democrats at the gubernatorial level. Another example is Texas where many house races (and the house vote overall in that state) were much closer than expected due to Cruz's close race.