I think Philadelphia - and Pittsburgh for that matter - is unknowable because no one there would dare admit they’ll vote for Trump, for fear of retribution.
Fortunately the voting booths are private.
There was a recent poll that had Trump up in Pittsburgh (+6%) but down big in Philly (-33%). You neutralize Philly by going after the black vote. Each vote Trump gets makes it more challenging for the Dems to create fraud.
It is great he is courting them. I just wished he would actually visit the inner cities instead of merely mentioning them.