I think the tweet @CaliDevotion posted shows that this framing by the media doesn't really edge out as the motivations or appeal some candidates have don't work out how pundits think they do, let alone that many people vote based on aspects of culture than they do any kind of ideology. Bernie is still #1 with Biden voters as a 2nd choice, for example. As well, when we look at the actual metrics, these divides don't really work out. Bernie won those without college degrees in New Hampshire despite the non-educated being who liberal elites often claim as most likely to be backwoods deplorables. Bernie also was #1 amongst both Democrats and independents. Bernie also performed similarly to Pete & Amy amongst voters who consider themselves "Conservative". What is clear is that Bernie's not popular amongst a very specific type of voter - the suburbanite affluent voter. These voters largely are the ones who made-up their mind last minute as they're the ones whose guiding ideology is simply anti-Bernie than pro-anything. These people would have voted for Warren if she was the most viable to block Bernie and the media narrative, I'm sure, would have been "Bernie can't bring together progressives!" as opposed to "Bernie only has progressives". A lot of the issue and kind of core conflict here is that the party's establishment at large love these kind of voters and appealing to them. They love building robots like Ossoff, Buttigieg, etc. to appeal to these very voters. The party pretty explicitly said in 2016 that they don't care how many poor black or brown people they lose in Milwaukee or Detroit, because they'll gain 2x white suburbanites in their place. (It actually ended up the opposite - for every one white suburbanite they picked up, 2 voters of color in economically-suffering cities stayed home).