If I remember the Jacobin's August analysis correctly, Sanders did very well among Latino communities and somewhat well in working-class white neighbourhoods (you know, the kind that delivered Trump his electoral victory in 2016) in the Democratic primaries.
Of course one can't generalise from a primary fought against Biden to a Presidential election fought against Trump, but it does suggest that Sanders' reformist agenda wasn't completely unappealing to people outside of the traditional urban-youth progressive class.
It's hard to say anything definitive about counterfactuals, of course, but it's not out of the question that Sanders would've done better than Biden had he gone to the general instead of Biden.









