China is now basically run by technocrats - scientists and engineers. (A society run by such is part of many technologists' fantasies, though I don't see a massive brain drain to there.)

New Labour in the UK was run by some ridiculously intelligent and erudite people. I was a fan and even I would say they did quite a lot of demonstrating that intelligence means you can do much bigger stupid things.

There are really quite a lot of frighteningly intelligent politicians. I'm not sure just increasing politicians' IQ will do much at all.