This may sound rather cold, but I think the key here is to find ways let idiots filter themselves and lift up people who actually try to better themselves. Stop protecting stupid people with seat belt laws and such, make information both contested and not contested easily available for people to research themselves, make education easily accessible and tailored to student ability as Spotted_Lady suggests, only allow the most skilled and well adjusted to immigrate into the country, and allow abortion so shitty parents who know they're shit won't bring another leech into the world. (Ideally I'd be pro-life, but you can't save everyone, so giving up someone that hasn't consciously "lived" seems the least fucked up, the same way it's less fucked up to increase the odds of old people dying of covid than to drag everyone else and the economy down to protect them.) Democracy is imperfect because everyone can't be an expert at everything, but if you can maintain a somewhat intelligent public, they can at least serve as a better check to the state, and filtering through merit and individual choices can potentially shift the ratio in that direction while keeping sweeping discrimination based on race, gender, sexuality, etc. to a minimum.