So, I don't know how original I am in this assessment, but I think if the Democratic Party turned to Economic Nationalism, that would be the end of the GOP, for good. I believe Trump won because of his success in the Rustbelt. If we take away Pennsylvania, Michigan & Ohio from Trump, Clinton is at 286 and Trump at 252. If we just took away Pennsylvania and Ohio, Trump is at 268 and Hillary is at exactly 270.
The workers there were mad about Free Trade, and probs would have voted for Bernie, whom, the polls show would have trounced Trump in the general (assuming his scandals didn't get the best of him).
So, if the Dems want to succeed, that is really all they have to do. The political divide in this country is still really close, but if the Dems wanted to actually ensure the end of the GOP for good, that is what they need to do, otherwise the GOP will remain a pretty strong competitor for much more time than is necessary.
Just some thoughts. I mean that's literally all they have to do, like, it's funny how it's just one single issue that screwed them over, and could end up killing the GOP forever if the Dems turned Left on this one single issue.