I believe you are on to something in your comments about the election results in Pennsylvania. Indeed I believe the basic issue here has much broader implications than you attest. The Democrat party's dominant internal forces are increasingly left wing, as the unexpeected rise of Bernie Sanders as well as other (equally looney ) figures like Elizabeth Warren attest. One result was that the formerly centrist Clinton political positions shifted markedly leftward in the recent campaign. The result in PA was as you described it, and I expect those forces were at work in Michigan, Ohio and many other places as well.
Interestingly the Republican hold on Srate governments, legislatures and Governor's seats continues a long term rise across the country, undermining the foundations for the growth of future Democrat leadership. Democrats may be undergoing a transformation analogous to that of the UK's Labor party, now in the hands of its unelectable far left wing element.
The fact that Michigan, the former home of Walter Reuther, is now a right to work state and has a Republican governor should tell us a lot about what has really been going on in the country for the past decade.