Sometimes the mumbo-jumbo is bullshit or dangerous.
By mentioning "deplorables and bitter clingers" you're admitting that much of the motive for such questioning among anti-intellectuals is rooted in politics and tribalism - and the premise that "intellectuals" are of the opposite or enemy tribe (leftists, liberals, feminists, Jews, atheists, pick your poison) and that therefore their work is inherently fraudulent or meaningless.
>Sometimes the mumbo-jumbo is bullshit or dangerous.
But anti-intellectuals tend to consider everything they don't understand, or anything that's part of the "establishment", to be "mumbo jumbo." If they had a credible, rational basis for their criticisms, rooted in an understanding of the domain they criticize, they would no longer be "anti-intellectual."
While, anti-vaxers, et al, are raised as examples of the harm anti-intellectuals can cause, many great harms have been caused or celebrated by intellectuals over the ages.
They really don't, though. At least, not a productive space. Intellectuals are quite capable of getting that traction on their own, and doing so on the basis of fact and evidence, rather than anger and a nihilistic mistrust of order and complexity.
You're putting a lot of effort into painting a heroic narrative of anti-intellectualism and of the harms of "the establishment" and intellectuals "over the ages," but that's a political stance, and one that assumes the anti-intellectuals are filling a necessary role in the ecosystem that intellectuals, themselves, cannot.
I put forth that there is no value to anti-intellectualism. Skepticism, yes. Questioning of authority? Yes. Opposing bad ideas? Yes. None of those are the particular domain of anti-intellectualism. Rather, those are all hallmarks of intellectualism.
The anti-intellectuals are the ones burning down the observatory so this never happens again. They're not helping.
Climate change denial in particular isn't a product of outsiders seriously questioning the scientific consensus on any grounds; it's a manifactured controversy, founded on outright lies by companies that stand to benefit if we don't do anything about it.
The reasons for anti-vaccine ideas are more complex, but they aren't the product of a serious engagement with the other side of the argument.