are themselves irrational.

But how can they know this? If they know this why don't they change?

They don't change because their beliefs are politically convenient. Because their beliefs justify the elite exercising power over the less elite. Because their beliefs justify behavior by the elite that serves the interests of members of the elite but destroys society.

Searching for an example of suicidal delusions that is not unduly relevant to either today's politics or yesterdays demons - unfortunately, such examples are necessarily obscure.

The nineteenth century British belief in benevolent enlightened imperialism justified a transfer of power and wealth from the unenlightened and piratical colonialists, to members of the British establishment more closely associated with the government, the elite and the better schools. Lots of people predicted this ideology would wind up having the consequences that it did have, that the pirates actually governed better, but were, of course, ignored.