I'm afraid you're confusing intelligence and reason
I can see why you'd think that, but no.
With only a below average intelligence, a person would not be equipped with the faculty to reason about complex issues - which is why you get political strongholds that are utter shitholes but have voted the same political party for 100 years, as an example.
If only the stupid were dogmatic there would be no problem, nobody would listen to them...
Neatly dovetailing into the politics example I gave above. Their vote is the same as your vote and has to be listened to equally. Which should transparently obviously be a problem, if we're worried about electoral interference. If its a genuine problem, swapping Pravda for Facebook won't solve it - only restricting voting and reshaping society to value intelligence would accomplish the task, but that would condemn half the populace to limited life choices and disenfranchisement forever.
This is one of those times where there are no easy options that change anything. The only easy option is to change nothing and live with the interference. Everything else quickly becomes a hard choice if anything is to be accomplished.