I think you are 180 degrees off. The Democrat elite started this 60 year slide with the creation of identity politics and by creating a hugely varied coalition of groups with one goal...hatred of conservatives and wiping out the traditional USA. That has now morphed into open hatred and resentment of white people.
All of this was created by Democrat elites and continues to be pushed and encouraged by Democrat elites. The rabid leftist coalition fully supports their insane elites and they have consistent goals. Why should they turn on their elites?
Because Leftists are basically insane and self-destructive. They must have nearby targets to destroy first. When they run short of "right-wingers", they turn on each other.
The so-called elites are riding the tiger. In their arrogance, they raise up monsters which they cannot put down.
Plus, it depends on what you mean by "elites." In a divided country one bunch of politicians defeats another bunch of politicians to win power, but nobody has the unquestioned authority that Establishment figures had 60 or so years ago. Everybody is suspicious and everybody in power is suspect.
And if the Democratic Party becomes too closely identified with a powerful elite hostile to the public, people vote against them. That's what happened with Hillary Clinton. She was seen as too elitist and voters dropped her.