It used to be said the key for Democrats was to win the east (Philadelphia) and west (Pittsburgh) and concede the middle. But the east has grown a lot bigger than just the Philadelphia area and now Obama has shown how a Democrat can simply run up huge margins in the entire eastern half of the state and win statewide. Republicans aren't going to win statewide any time soon if they don't start
making up for lost ground in the suburbs. In fact, this McCain deficit in the Philadelphia suburbs was mirrored in suburban communities across the country; it wasn't just concentrated in Pennsylvania.
I will add this, in term of percentage of the vote, John McCain did slightly better in Philadelphia than Trump did.