Are there simple answers that answer this question, or is the mere act of asking the question what raises the hackles?
Whats always perplexing to me (and my biases) is that each party appeals to certain constituencies, and yet never delivers to them.
For instance the Republicans tend to appeal to rural voters. I’d would surmise largely on social issues. Its never really been able to deliver on those issues, and it probably never will.
The Democrats tend to appeal to poor urban wealthy urban voters. Its has however really turned its back on them to become more centrist.
Each group still solidly votes for its party. I have a sneaking suspicion it has less to do with delivering on the goods than it does each groups deep seated mis-trust of the other.
Prior to WWII both parties were centrist, with liberal and conservative wings, anyone remember the Dixiecrats? It was the move towards legislation of social equality that really accelerated both parties moves away from the center.
What benefits did we as a nation get from each party moving away from the center? I think we can all pretty plainly see the costs. Political deadlock and a culture war that can never be, “won.”