Pennsylvania isn't Midwestern but it's not "Northeast liberal" either.
Well, sure ... but it's still "Northeastern." This is the problem with political junkies talking about geography (or anything, for that matter) - they just can't remove politics from the conversation. Cook County, IL (Chicago and some inner suburbs) voted 74% for Hillary Clinton. Woodford County, IL (fairly wealthy exurban Peoria) voted 68.0% for Donald Trump. Both are 110% nothing but Midwestern. Their political differences just simply cannot be explained through geography, and that is the end of the story. Nobody in Pennsylvania would identify as "Midwestern" just because they have differences with other folks in the region known as the Northeast.