I wonder where exactly it all went wrong: Did the education system fail half the country? Is the church too influential and powerful? Just what is it?
Or is it some conglomeration of factors far more subtle that we can only hope to guess at? Is there a way out of this shit?
I'm far underqualified to give a definitive answer to this, as I have done very little research into the matter, but I think it might have started with WWRD or what would Reagan do? Once you start to deify a politician it will naturally lead to the corruption of the party, especially once that politician passes away and can no longer update their stances given the current societal climate.
Every Republican is trying to be the next Reagan in the eyes of their voters, but there is no way of knowing if Reagan would still hold the same stances today that he did when president. It also leads to the party no longer standing for a policy matter and instead the party is whatever the leader says it is (and keep in mind, I'm not claiming Democrats are immune to this, but they currently don't seem to have a leader like what Trump has been able to do).
This gradual shift away from policy and instead to leader rule can work so long as the leader is a reasonable person who knows that they are human and can be wrong and are willing to shift their ideas given new evidence, a quality that is completely nonexistent in Trump. This lack of humility may have actually been what lead to his rise to power. Many Republicans have decried the "weak" Republican presidential players of late and their complete lack of willingness to toss cooperation to the side. In walks Trump who "says it like it is" and "says the things I like and attacks the people I don't like". The focus on fear of illegal immigration, the fear of changes in society (such as gay marriage, trans people in general, and globalized economies), and turning everything into a fight of good and evil, with the other side being evil, naturally leads to what has happened.
On a side note, you might also be able to point to the rise of the 24 hour news cycle as the real catalyst for what's happening today.