I've generally heard the randomly, unbacked quote: "Up to a third of the population is easily swayed by any kind of persuasion/marketing". I don't know the exa

I've generally heard the randomly, unbacked quote: "Up to a third of the population is easily swayed by any kind of persuasion/marketing". I don't know the exact percentage but it is certainly non-zero. Given that many elections in recent memory are won by margins of <10%, it doesn't matter if the majority has a BS detector since that majority isn't the target of "mechanized persuasion" aka A/B testing based advertising.