the film debunks the meme that the dems of old became the Republicans of today.
The soul of the dem party has never changed.
I would say that it would be nearly impossible to change the soul of any political party without a dramatic purge.
For the benefit of those who have not yet seen the film, because clearly you have and you understand this, there never was any such purge. The Democrat Party has always been about theft - first of the labor of blacks, later the labor of everyone via taxation and regulation. After slavery was over, and we moved into the 20th century, they could no longer be so open about it, so they developed a scam that they were progressives. That worked for quite a while until that mode of thinking, which included eugenics (personified by Margaret Sanger’s open desire to exterminate in the US via birth control) became associated with the Nazis. So, they changed the con - but the goal remained the same. Now they seek to control all wealth via regulation of all activities - because only government can help us navigate through life’s complexity. They claim to be compassionate while trying to literally steal everything from us.
So they changed how they represented what they do, not WHAT they do.