I don't think many stupid ones get into a position of power. There are many smart people that play stupid to appeal to their base voters. Sure there are some that slip through but most of them are quite intelligent and just playing a character that best reflects the people that voted for them.
I have also met many very bright kids and adults here - the public education system is not giving many of them the opportunities they deserve. It is not that difficult to fix.
The stupid ones are clever enough to ensure they employ people even more stupid - surround yourself with stupidity and you look good (as with Boris in the UK).
Have you ever listened to the in charge of education here, Briones i think is her name. Pension her off should be the first step.