Off topic from the video AI thread, but to elaborate on your point: people believe what they want, based on what they have been primed to believe from mass media. This is mainly the normal TV and paper news, filtered through institutions like government proclamations, schools, and now supercharged by social media. This is why the "narrative" exists, and news media does the consensus messaging of what you should believe (and why they hate X and other freer media sources).
By the time the politician says it, you've been soaking in it for weeks or months, if not longer. That just confirms the bias that has been implanted in you.