I could see a 50/50 national election looking something along these lines:
I could see all of that happening except Pennsylvania... Democrats simply get too big a margin in Philly and the inner burbs. I don't see how that changes anytime soon.
Indeed. The GOP has talked about PA for years. What votes are they picking up out of the T that they don't already have? SW PA has gone their direction and they still can't get all that close. Moderation on a national level would be the only way to even SLOW DOWN the Philly 'burbs drift towards the Democrats.
We're getting to a point where the national map just favors the Dems and that's that. The GOP had a huge electoral advantage two separate times in the 20th Century; it's far from unprecedented.