As I said... wilfred social science...
Here's a nice visual graph that I like: https://www.pewresearch.org/fact-tank/2014/06/12/7-things-to...
Go put your finger on the republican line and see where it moves.
There has been analysis done by many groups which have confirmed where the political polarization derived heavily starting with gay rights. The republicans who had 'closeted' homosexuals moved left. Trump literally started a fight with russia and the middle east trying to benefit homosexuals. https://www.nbcnews.com/politics/national-security/trump-adm...
The republicans clearly moved left and it was the right thing to do. Whereas Truman != Obama. It's rather easy to objectively see both parties have moved left.
I feel like this is rather objective fact. The better discussion, why is this the case? Is it perhaps where the democrats have gone is the right place both parties eventually end up? Or are we about to watch 2nd civil war?