I think the political divide has already been around for a long time now. I've seen indications of regional and cultural divides for much of my life. I've heard of people talk of "Coastals" and "Flyover Country," which would indicate such divides. There have also been more pronounced class divisions which may not have been quite so sharp or emphasized prior to Reagan. Even liberals started embracing the mantra of the "Material Girl," abandoning their previous sympathies for the working classes.
Also, I've noticed a lot of indications and charges of hypocrisy coming from both sides, as if people are simply playing a political game. It doesn't appear to be motivated by any genuine political principles or righteous cause; it's simply a matter of whoever dies with the most toys (or the most votes) wins. The rhetoric has turned into tit-for-tat gainsaying, with little to no attention paid to actual political principles or ideals.
A political divide would be one thing if there was actually something to be divided over - something meaningful and significant in the American political consciousness. But when it's reduced to what we have now, it's as if people are fighting over their favorite TV show or sports team. There is no depth, no true principles, and no real substance to this at all. This is all so empty and jaded.