Because there's literally no evidence to suggest that it will?
It's funny because regardless, PA has gone Democratic for an entire generation now. Democrats scored 10%+ margin in 2008, which shows they have a high ceiling there, yet Republicans can't even get 1 win in something like 25 years. Not to mention 1988's GOP winning margin was < 2%
This is the kind of state where unless there are some substantial, blatantly obvious pro-GOP trends, that it is best to assume it will just go Democratic but there is at least a marginal chance it won't. With Trump on the ticket, they would be lucky if their US House delegation didn't get eviscerated as they lose the state at the presidential level.
It's a stunningly inelastic state. Unless you have literally the perfect Republican candidate for PA and the absolute worst Democratic candidate for PA, it's not going Republican anytime in the next few cycles.
