[adifgoi0nio]

>No society has tried selecting random people in adulthood to put in charge.

This is a practice called 'sordition'. As evidenced by the fact it has a name and a Wikipedia article, it is not something you just invented. It was famously used in Athens and is how American juries are selected today,

I think I would support a revival of sordition. Perhaps we could start small, perhaps by selecting one representative for each state at random.

[tlb]

Sortition happened in adulthood, though. The interesting (and untried) experiment is to designate people early in life, so they can grow up being educated and prepared for their future responsibility.