I don't think they were more attuned to the working class and unions so much as there were more unions to rely on as a voting bloc. As a political power base, unions are shrinking and their former members still need work.
Unfortunately for the Dem's, they can't stop or reverse the declining union enrollment and so, through no particular fault of their own, they've failed their voting base.
I think it's short-sighted to look at the Trump election in terms of larger political trends, at least in the U.S. Trump is a unique candidate in that he brings a certain economic nostalgia that is difficult to emulate. Probably one of the most erroneous insults directed at Trump during this election (and something I mentioned repeatedly) is the mistake of referring to him as a reality TV star.
Trump represents a heady time of American economic success that makes him very appealing to people who want more American economic success. My parents still have a copy of the Art of the Deal. I've read it. Trump was only a reality star because his brand of economic success was so high that it could carry a tv show. To the best of my knowledge, the GOP does not have another such individual waiting in the wings.
Additionally, we can't ignore the Obama backlash. In this age of social media where nothing ever disappears, the members of the losing party spend their entire time reliving their slights, real or imagined, while psych'ing themselves up for the next election.
I think the GOP has bigger long term issues than the Dem's and Trump's win doesn't change that, it simply delays it. Something that I also said during the campaign - that him winning might actually be worse for the GOP in the long run because they wouldn't address some of their structural issues as the victors.