mass media exists, and so does poor education.
As usual, I put a lot of blame on Reagan.
The education question in the US is extremely complex and I can't get into that now. But I will say that I received an excellent education in the public school system between the mid-1950s and mid-1970s (just in time before it headed drastically downhill). And my children were able to get excellent educations (by today's standards, but not as good as mine) through a combination of solid "pre-schooling" (ie before kindergarten), good neighborhood schools (we lived in a moderately affluent and progressive area), both of them were able to get into a superb Magnet/STEM high school, and in college majoring in sciences (as opposed to "biz-nus").
But as for mass media, when radio began in the US the FCC (Federal Communications Commission) was established and it had a rule called "The Fairness Doctrine" that applied to radio, and later television, which required that when political issues were discussed, there had to be "fair" presentation of both sides. Not necessarily (as some thought) "equal time", but a reasonable offering of both viewpoints.
Reagan quickly gutted the FCC (Republicans abhor regulation in any form) and the fairness went out the window.
Broadcasters such as right-wing AM talk radio and Fox or Sinclair "News" as we know them simply could not have existed before the 1980s.
Imagine what happened in following decades as the interwebs grew and eventually dominated the dispersal of "information" ....