I see it as it's been growing almost exponentially for two-ish decades. There was always some division. The very partisan stupid impeachment of Clinton (who I wasn't a fan of, but that was kinda dumb, though he shouldn't have lied I guess), then the GWB Election really fractured things. It kind of came right as the time of the 'internet age' so social media by 2010 was super prevalent. The means for propagandizing and polarizing people got extremely better over the last 20 years. Before Trump was even elected though, in general democrats hated Bush especially his second term. Republicans hated Obama, Trump... well that's obvious lol. I think it was heading for this, no matter who was elected though. There was so much vitriol for both Trump and Hillary we were in for a crazy time. I just think the tools for divide and conquer are so advanced now, the technology, and AI algorithms giving us positive reinforcement, changing search algorithms to show us what we want to see, has created an America that is going to be hyper-polarized. So I personally believe the reason why that is, is because the tools for divide and conquer of the US have been refined through fire so to speak.
https://www.dailymail.co.uk/news/ar...calling-news-network-money-making-cancer.html
https://www.bariweiss.com/resignation-letter
Just posting those as some of the people in the media are quitting saying basically the same things about the media.