Class-warfare and jealousy. The twin rails the Dim loco-motive,with the focus on loco,runs on.
Class warfare, most definitely. But it's more than mere "jealousy", or even Envy, for that matter.
Progressive Democrats may rail against "wealth" and "privilege" and so forth, but they don't really have a problem if they themselves can enjoy the fruits of both.
This is so because they view themselves as special - spiritually enlightened and possessed of all the "correct" opinions. Nor do they deny wealth and privilege to people like Bernie Sanders (or Tom Steyer or Mark Zuckerberg, for that matter).
But if you are wealthy and use your influence to support the cause of liberty (e.g.- the Koch Brothers), then you are an evil monster who must be destroyed. If you are not even magnificently wealthy, but only a successful businessperson who employs a few hundred people, makes a few hundred thousand a year, and supports Republican causes, then likewise you are a threat.
And it's not just because the Sandernistas want to take your money away from you (though they'd gladly do that). It is because of what you represent: a threat to their worldview, in which "fairness" is determined by equality of outcome, not by equality of opportunity, and wherein it is the role of government to use its monopoly on force to effect such an outcome by means of regulation and forcible redistribution of wealth.
In short, they need to elevate themselves by leveling you, because they do not share the idea of hard work and self-reliance as virtues, and liberty and property ownership as inalienable human rights.