The central idea is that the Enlightenment, and all its principles of democracy, equality, reason and humanism, was a catastrophic mistake, which has led to self-destructive spiral of decline which is destroying western civilization. The proposal is that the monolithic nexus of academia, media and government bureaucracy that enforces ideological conformity under the guise of enlightenment values needs to be collapsed. The system of government to replace it is an updated version of the monarchies that preceded the Enlightenment, powerfully supported by information technology (a technosociety) that will be run by strong leader rather like a corporate CEO, and that this will allow for the freedom that has has been suppressed by the mediocrity of democracy.
This may seem far-fetched, but Vance and Bannon have certainly been strongly influenced by it, and the actions of the Trump administration against woke culture, illegal immigrants, the Smithsonian etc certainly seem to align with it.
It is also a philosophy that effectively declares intellectual war on humanism. I believe it has to be taken very seriously, and that it is important not to get caught into criticising its details, or pointing to its factual errors.
Some reading (if you search online you will find that a lot of items are behind paywalls – these are not):
https://time.com/7269166/dark-
https://en.wikipedia.org/wiki/
https://newrepublic.com/
https://publicmedievalist.com/