Pennsylvania may be Joe Biden's home state. But I don't think that you can term it as a blue state. Even now, out of the two PA senators, one is Republican (Pat Toomey). Trump won the 2016 elections in PA, although by a wafer-thin margin (by 44,292 votes). As per the opinion polls, Biden may be well ahead in PA. But let's not forget the fact that the same was the case even in 2016. PA is a part of rust-belt, and Trump supporters are wary of identifying as such in the public.