Her initial conclusion has an ad hominem quality to it: meritocracy is resented because those outside the "elite" know that they're absolutely excluded by an objective lack of qualifications.
The old Establishment types were resented, but only because their wealth and power were perceived as "undeserved." Those outside could at least feel they were cleverer and savvier, and they could blame their failures on "the system." Nowadays, successful Americans, however ridiculously lucky they have been, often smugly see themselves as "deserving." Meanwhile, the less successful are more likely to feel it's their own fault—or to feel that others feel it's their fault—even if they have simply been unlucky.
Applebaum also sees that there's more to anti-elitism -- and outside of her timeline, an earlier generation called it anti-intellectualism -- than simple envy. She cites Ginni Thomas, the wife of Justice Thomas of the Supreme Court, who denounces an "elite that thinks it knows better than we know." This is the anti-elitism I've seen for the last two years. What makes someone elitist to the reactionary mind isn't education alone, or even education itself, but the perceived presumption that education entitles the alleged elitist to "tell us how to live." Someone with the same degrees who espouses libertarian principles and praises the innate know-how of the common man wouldn't be resented as much, I presume.
Anti-elitism isn't entirely a matter of envy or resentment. Part of it has to do with the instinctual sense that people can get on without "book learning," and the corollary suspicion that too much book learning actually detracts from the common sense that comes only with hands-on experience. Mark McDonald, one of the readers who commented on Applebaum's article, expresses this viewpoint:
The anti-elites do not resent hard work, education, etc., they just hate that these Ivy League are all the same and really not that impressive. This has nothing to do with upward mobility. It has to do with the incompetence of the elite and their inability to lead. Democrats used to use the same nonsense. Have you not been alive long enough to know this Anne? Sometimes a bunch of people reading the same books assigned by the same professors at the same universities become like all other elites in all previous sociieties: inbred and out of touch; and this despite their sometimes humble backgrounds.
Andrew Fisher, another respondent, seconds this viewpoint somewhat:
People tend to equate "education" with being intelligent,smart, more aware etc. It just isn't so. I voted for Jimmy Carter in '78 [sic] because he was "smarter" than Reagan and had been more effective during the debate. Reagan's first 100 days changed my views forever. We need leaders who are committed to a ideal.
Another factor in anti-elitism is arguably inherent in democracy itself, at least as understood in the U.S. Our understanding of the concept comes from Thomas Jefferson, who asserted in the Declaration of Independence that government derives legitimacy from "the consent of the governed," without qualifying either consent or governed in any way that explicitly imposes an intelligence test on anyone. Jefferson himself put restrictions on whose consent was needed, but they weren't meritocratic in any way, except to the prejudiced minds of his time. But while he thought that the franchise belonged to those who had a stake in society in the form of property, people today believe that everyone has a stake in government because government influences all our lives. If it affects us regardless of our educational attainments, those shouldn't decide our ability or right to influence government. These observations may beg the question of whether democracy is actually the ideal form of government, so long as you believe that "objective" national or global interests require that measures be taken regardless of majority will. Some people will never accept that premise, whether on moral grounds or a failure of conscientious imagination. Some will always insist that the national or people's interest is whatever the people say it is, while anything else is an elitist imposition on everyone else. As long as we have democracy, these arguments will be part of the debate. Why they are argued more forcefully at times like the present, rather than why they're made at all, may be the more important question to ask right now.