People are imagining this like (if you'd forgive the analogy) Dragon Ball Z, where Vegeta is the big villain and we all need to rally around defeating him, but then an even bigger and more evil villain appears, Frieza, so now we team up with the still-evil Vegeta because he's more good than Frieza.

That's not what this is. This is Reaganites tipping their hand that they and the democrats are fundamentally on the same team, they are all part of the neoliberal establishment, and Trump, in his instability, is rocking the boat.