IQ is genetic. Smart parents usually have smart kids. Dumb parents usually have dumb kids. It's not their fault, it's just genetic. And smart people are usually attracted to other smart people, and somehow dumb people manage to find each other.
So if a group of evil people, say Bolsheviks, wanted to elevate themselves as a smart group of people, wouldn't it be in their own best interest to either enslave via bribery & blackmail all of the people who are smart? And if they couldn't be bribed or blackmailed, to kill them? That way, they would become the smart people. Or they would own all of the smart people and could control them to do their evil bidding.
Once Smart people realized what had happened to them, how long would it take for them to organize themselves and deceive the Evil people and knock them out of the picture?