AOC is too much of a culture warrior to win back the old rurals that Bernie won in '16 and lost this year. Harris corners the black vote, and like EVERY DEMOCRATIC PRIMARY, their choice is the winner.
You sound very upset about this. Hmm... wonder why.
That said, I don't think Harris would be a much better fit for the "old rurals." She's a "culture warrior" herself who literally made banning Trump from Twitter part of her campaign platform and talked about it in the debates. I don't think the old rurals would care much for either of these candidates. But yeah, they probably would ultimately side with the one who is more moderate and experienced over the one who is almost entirely known for being a gadfly on Twitter and is a member of the DSA. Because like black voters, they are generally a more moderate and pragmatic group.
And being too radical IS why Bernie lost their vote this year, by the way. I need you to understand that. You can't win them "back" because you never had them. They just didn't like Hillary. They never liked Bernie. And they'll take a moderate they do like such as Biden over him every time, as we clearly saw. There is no widespread secret desire for socialist revolution in the heartland of America. There never has been, and there never will be.
