That's authoritarianism. You don't see the CCP edging closer to a civil war based on propagated polarising. AFAIK, that's never been achieved in human history. I'm sure it's unlikely to happen, but between all the international targeting from Russia, China, etc. and then the US's own media and governments, the US is soaked in propaganda more than anywhere else. Absolutely surrounded by it.

But this is the interesting part. The more someone is propagated, the less likely they are to realise it.

America doesn't even need to do that. It just convinces people to not trust anything that doesn't come from pre-approved sources and that works well enough.