Complicated term. Generally figures of hatred from the right and the left.
To an extent, the "liberal elites" are those who were successful in the liberal (and then NeoLiberal) order of the mid-late 20th century and early (pre 2008Crash 21st century.)
They are those who believe that sensible centrism is ThirdWay, a SocialDemocracy that has made peace with, and doesn't threaten capitalism.
RightWingPopulism accuses the "liberal elite" of being out-of-touch, snobbish, not caring about the WorkingClass.
Could there be something more than rhetoric to this?
A disturbing idea (ConsumTariatPolitics) :
And we're seeing the rebellion of the "have-not" ConsumTariat against the elites.
Most traditional leftists assumed this would be the poor against the rich. But what if it's the "information / culture poor" against the "information / culture rich"? ie. the "CognitiveElites"?
That would fit the pattern of poor uneducated siding with the super-wealthy (but playing dumb) populists like DonaldTrump against the middle-class who have some higher education.