I'm almost your age, and I think you're mostly right.

I believe the issue started with Nixon, though. That was when the Republican Party made the dramatic switch to being a systematically criminal party.

When Ronald Reagan(*) was elected, the Republicans productionized(**) lying and criminality into a very palatable package.

The key strategy was to convince people to choose to believe what they wanted to be true, rather than what was actually true.

Once you have decided to "Divorce old barren Reason from your Bed/And take the Daughter of the Vine to Spouse", then you can't really go back until everything collapses.

So you're basically right that Reagan was the dividing line, but the first cut was made by Nixon. Damn all these psychopaths to Hell, would that there were one.

(* - I was going to make a 666 joke here, but 666 actually signifies "The Great Work Accomplished".)

(** - unfortunately, this is really a word these days.)