When I read it correctly, then one should correct these misperceptions in long-term attitude change when the resulting political mindset runs counter to one's own... The fact stated at the beginning, that people adopt what they believe to be the general trend, is what's truly frightening since it can so easily be exploited by mass media and algorithms.
We've known that for forever though. Advertising exploits that fact to great effect. A lot of people either go with the crowd or have viable alternatives crowded/drowned out by what's popular for being popular. It makes media consolidation a huge concern. It's also why the entertainment industry is so desperate to fight piracy. It's less about the sales figures than it is about the power to act as a gatekeeper that shapes our culture and dictates how/when we get access to it.