Kevin Drum, writing in Mother Jones, astutely notes:

“[I]t’s not that the working class has abandoned Democrats. It’s just the opposite: The Democratic Party has largely abandoned the working class.” 

 It’s an excellent article, and I encourage you to read the whole thing.

He goes on to describe the animosity that existed between the “New Left”, as he calls it, and organized labor. Specifically, to paraphrase him a bit, there was something of a culture clash, and so the  “New Leftists” were disliked by the old-school working class.

It’s this clash, of course, which has caused such a problem for the Democratic party, and the article does a good job of explaining how it still impacts them even today. And (forgive me a bit of self-promotion) it’s sort of related to the issue I wrote about here.