Luee,
The word liberal is defined as "tolerant of the beliefs and opinions of others, open to new ideas, " which means it describes a lot of Americans and means it cannot, by definition, be an "elite. "
Elites, by their nature, are conservative wrt to the status quo that fosters them, and reject ideas and beliefs that pose a perceived threat. So, yes, people in academia could form an elite, potentially. Or wealthy people in extractive industries. But once an attitude of elitism takes hold in some societal niche, they are no longer in any way describable as liberal, in the word's actual meaning.