Of course it is. Trump's a lunatic.
But you dont get shut of his movement unless you draw the right conclusions and unite under a clear set of principles.
The danger now is that the Democrats rally around and shift rightwards in an effort to pick up more working class votes. That's not where the working class are and it's not why the Democrats lost the election. They lost the election because they didn't maintain working class living standards and they lost their support - and they lost other sections of society too with a rank foreign policy agenda.
It depends on what you mean by left and right.
The Democrats didn't lose working class votes b/c of economic issues. That might be what those voters are saying, but what they mean is the Democrats lost them on social issues. Cultural issues. Them's the facts.
Democrats can move to the center on those issues while still taking a non-negotiable stance on things like no tolerance for nazis, racism, etc, etc. Democrats shouldn't be dying on the hill for boys at birth playing girls' sports in my opinion - it's such a niche issue it's just noise and makes Democrats look like they don't understand common sense.
We will have to agree to disagree on the economic front. Democrats never win on policy/economic type arguments b/c this stuff is more complicated and less based on emotion. While it's obvious to many that unregulated capitalism run amok will ultimately hurt the working class, their voters don't see it that way.