I don't agree with everything in that article, but I do think it's on to something with the Harris/Walz ticket, and I would call it "authenticity." Most politicians speak, and you pretty quickly realize you are listening to a politician -- a shady salesperson hawking ideas bought and sold with votes. With the truly gifted politicians you don't get that sense. You feel like you are just listening to someone with a lot of common sense telling it like it is and presenting ideas against problems. When I listen to Harris and Walz, I don't feel like someone is trying to sell me a lemon.
Trump is interesting in this regard. I think he is authentically an asshole, moron and disruptor of the status quo. That speaks to the politically disenfranchised who value his authenticity in that regard. But I don't think he's authentically attempting to make anything better for anyone other than himself and a small minority of would be oligarchs. He's the ultimate manifestation of this meme, and a good number of people have been made so angry and afraid that they cannot recognize they have a lot more in common with the minority sitting with them at the table of the common man than the wealthy asshole who has stopped by to rile them both up.