Moved to the US when I was a kid, but I have clear memories of watching channel 1 every day with grandma. This answer probably will apply to people 40 and over. For the record I'm not that old yet!
Back then the Internet wasn't really a thing, so TV was really the only source of news. And even through it was understood that most of the things you heard on the news were lies, it was hard to say what exactly was lies and what was news. So, you ended up believing some things, and then you believe more and more... It's easy to slip into this. And I'm sure things haven't really changed. At least from what I've seen.