Agree that people watching Fox is not a huge number but it's just one source of misinformation infection.

From '91 to 2021 Rush Limbaugh's show had 15 to 26 million daily listeners depending on the source you choose(EIB claimed the higher figure, of course, kinda like Trump claiming the biggest inauguration ever) !

Also, you are not considering the multiplier effect of coordinated misinformation campaigns.

Of course. But again, this is not a new thing. The influence of Hearst's or Pulitzer's yellow journalist rag papers wasn't just limited to their direct circulation, either - those stories were picked up by the political machines and Boss hall's and their own propaganda outlets as well. The Birchers' lies weren't limited to recipients of their newsletters or attendees at their meetings, nor those of the Moral Majority to its members, nor the 700 Club to its viewers, nor The National Review to its subscriber base.

I think you're feeling nostalgia for an electorate that has never existed. Democracy doesn't require the voters to be better than they actually are to be healthy. The electorate has always acted on a mix of myths, biases, falsehoods, half-truths, and prejudices - on all sides of the political spectrum.