I'm a member of a small leftwing party which has progressively been more and more trounced in the last couple of election and the thing I've been saying internally for quite a while (since before the collapse started, even) is exactly that the people heading the party are such a socially narrow group with such a limited set of life experiences (thirty-something well off middle class children of well off middle class parents with straight from highschool to university to politics paths) that they're disconnected from the life experience of the overwhelming majority of people out there and don't have experience in an environment with actual concrete competency metrics were you can't just excuse away your failures with some bollocks about the external environment (as they just did in an e-mail to party members after they're recent "worst ever since the party was formed" electoral results).

Oh and from conversations I had with a member of parliament some years ago, they definitely see themselves as an elite within the party itself which knows better than the rest.

Anyways, I know the US is different with its de facto political duopoly, but it's funny this dynamic in politics of thinking bubbles forming from people whose upbringing and life experiences is wholy detached from that of pretty much everybody else coupled with them feeling that they know better than the rest, a feeling entirely built upon them telling each other "you're so right" in one big circle jerk and the mindless adoration of people for whom Politics is just another form of fandom and always adoringly agree to anything the "stars" from "their side" say.