According to the narrative, Bernie could have won over working class whites, which Hillary lost in places like Lackawana and Luzerne counties, PA; as well as places like Youngstown, OH. This seems plausible. But if this was true, he should have won these places in the primaries as well, no? Had he been able to win working class whites in the primaries, he may have been the nominee. Evidence is, they crossed over for Trump, as opposed to sticking with Bernie.
I think he would have if Trump hadn't run. They are also concerned about immigration as well as jobs, so Bernie was only half the package.