There is a lot I would be keen to talk about regarding this article (kudos on the accountability-not-cancellation point especially!), but I will stick to one aspect of it; I don't think 'conservatism' is on the decline in America. The conservatism of Eisenhower's era is certainly gone - the old collectivist lens of conservatism - but the direction taken by America's right since Reagan is still very much in play.

I would say the paranoia you mention here is major factor in generating increased support for America's right wing. You even mention reasons for this in the article - anxiety among the US' white, especially working class, population that they are being left behind. Academics and tech giants may seem like the new elite class that will champion the center-left's rise, but this is not representative of a broader shift in American culture. Overall, the US is becoming divided, resulting in both 'sides' making gains, with the center becoming more sparse.

This is by no means a good thing, of course, but this seems more accurate than viewing a decline/collapse on the right through the loss of Trump.