I actually don’t see this happening a lot aside from a few commentators. For the most part, the same exact people who were doing the “not another (white) man” bit to Bernie in 2016 have now lined up behind Biden.

Ultimately voter behavior is complicated. It’s true that voters in general don’t necessarily just look for a candidate who shares their demographic characteristics, but they do vote based on group interests. Look at Kamala Harris. It’s pretty safe to say that she would be a much stronger candidate were it not for her record as California AG.

But also there’s a sizable chunk of the electorate that doesn’t vote on either policy or identity. They vote on personality. They decide they like a candidate and then ascribe their values or policy position to that candidate whether it’s true or not. You saw this a lot in 2016 with voters who switched from Sanders to Trump. They were largely operating on a very superficial level. They liked the populist rhetoric of both candidates, but they didn’t pay too much attention to the wide gulf in terms of policy.